Merge branch 'master' into index-lifecycle

buildSrc/version.properties

@@ -4,7 +4,7 @@ lucene            = 7.5.0-snapshot-608f0277b0
 # optional dependencies
 spatial4j         = 0.7
 jts               = 1.15.0
-jackson           = 2.8.10
+jackson           = 2.8.11
 snakeyaml         = 1.17
 # when updating log4j, please update also docs/java-api/index.asciidoc
 log4j             = 2.11.1

client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java

@@ -163,8 +163,11 @@ import org.elasticsearch.search.aggregations.pipeline.derivative.DerivativePipel
 import org.elasticsearch.search.aggregations.pipeline.derivative.ParsedDerivative;
 import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
+import org.elasticsearch.search.suggest.completion.CompletionSuggestionBuilder;
 import org.elasticsearch.search.suggest.phrase.PhraseSuggestion;
+import org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder;
 import org.elasticsearch.search.suggest.term.TermSuggestion;
+import org.elasticsearch.search.suggest.term.TermSuggestionBuilder;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -1151,11 +1154,11 @@ public class RestHighLevelClient implements Closeable {
         List<NamedXContentRegistry.Entry> entries = map.entrySet().stream()
                 .map(entry -> new NamedXContentRegistry.Entry(Aggregation.class, new ParseField(entry.getKey()), entry.getValue()))
                 .collect(Collectors.toList());
-        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(TermSuggestion.NAME),
+        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(TermSuggestionBuilder.SUGGESTION_NAME),
                 (parser, context) -> TermSuggestion.fromXContent(parser, (String)context)));
-        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(PhraseSuggestion.NAME),
+        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(PhraseSuggestionBuilder.SUGGESTION_NAME),
                 (parser, context) -> PhraseSuggestion.fromXContent(parser, (String)context)));
-        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(CompletionSuggestion.NAME),
+        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(CompletionSuggestionBuilder.SUGGESTION_NAME),
                 (parser, context) -> CompletionSuggestion.fromXContent(parser, (String)context)));
         return entries;
     }

client/sniffer/licenses/jackson-core-2.8.10.jar.sha1

@@ -1 +0,0 @@
-eb21a035c66ad307e66ec8fce37f5d50fd62d039

client/sniffer/licenses/jackson-core-2.8.11.jar.sha1

@@ -0,0 +1 @@
+876ead1db19f0c9e79c9789273a3ef8c6fd6c29b

distribution/packages/src/common/systemd/elasticsearch.service

@@ -6,6 +6,7 @@ After=network-online.target
 
 [Service]
 RuntimeDirectory=elasticsearch
+PrivateTmp=true
 Environment=ES_HOME=/usr/share/elasticsearch
 Environment=ES_PATH_CONF=${path.conf}
 Environment=PID_DIR=/var/run/elasticsearch

docs/reference/release-notes/7.0.0-alpha1.asciidoc

@@ -21,4 +21,10 @@ Aggregations::
 * The Percentiles and PercentileRanks aggregations now return `null` in the REST response,
   instead of `NaN`.  This makes it consistent with the rest of the aggregations.  Note:
   this only applies to the REST response, the java objects continue to return `NaN` (also
-  consistent with other aggregations)
+  consistent with other aggregations)
+
+Suggesters::
+* Plugins that register suggesters can now define their own types of suggestions and must
+  explicitly indicate the type of suggestion that they produce. Existing plugins will
+  require changes to their plugin registration. See the `custom-suggester` example
+  plugin {pull}30284[#30284]

docs/reference/setup/important-settings.asciidoc

@@ -14,6 +14,7 @@ The following settings *must* be considered before going to production:
 * <<heap-size,Heap size>>
 * <<heap-dump-path,Heap dump path>>
 * <<gc-logging,GC logging>>
+* <<es-tmpdir,Temp directory>>
 
 include::important-settings/path-settings.asciidoc[]
 
@@ -31,4 +32,6 @@ include::important-settings/heap-dump-path.asciidoc[]
 
 include::important-settings/gc-logging.asciidoc[]
 
+include::important-settings/es-tmpdir.asciidoc[]
+
 include::important-settings/error-file.asciidoc[]

docs/reference/setup/important-settings/es-tmpdir.asciidoc

@@ -0,0 +1,23 @@
+[[es-tmpdir]]
+=== Temp directory
+
+By default, Elasticsearch uses a private temporary directory that the startup
+script creates immediately below the system temporary directory.
+
+On some Linux distributions a system utility will clean files and directories
+from `/tmp` if they have not been recently accessed. This can lead to the
+private temporary directory being removed while Elasticsearch is running if
+features that require the temporary directory are not used for a long time.
+This causes problems if a feature that requires the temporary directory is
+subsequently used.
+
+If you install Elasticsearch using the `.deb` or `.rpm` packages and run it
+under `systemd` then the private temporary directory that Elasticsearch uses
+is excluded from periodic cleanup.
+
+However, if you intend to run the `.tar.gz` distribution on Linux for an
+extended period then you should consider creating a dedicated temporary
+directory for Elasticsearch that is not under a path that will have old files
+and directories cleaned from it. This directory should have permissions set
+so that only the user that Elasticsearch runs as can access it. Then set the
+`$ES_TMPDIR` environment variable to point to it before starting Elasticsearch.

libs/x-content/licenses/jackson-core-2.8.10.jar.sha1

@@ -1 +0,0 @@
-eb21a035c66ad307e66ec8fce37f5d50fd62d039

libs/x-content/licenses/jackson-core-2.8.11.jar.sha1

@@ -0,0 +1 @@
+876ead1db19f0c9e79c9789273a3ef8c6fd6c29b

libs/x-content/licenses/jackson-dataformat-cbor-2.8.10.jar.sha1

@@ -1 +0,0 @@
-1c58cc9313ddf19f0900cd61ed044874278ce320

libs/x-content/licenses/jackson-dataformat-cbor-2.8.11.jar.sha1

@@ -0,0 +1 @@
+8b9826e16c3366764bfb7ad7362554f0471046c3

libs/x-content/licenses/jackson-dataformat-smile-2.8.10.jar.sha1

@@ -1 +0,0 @@
-e853081fadaad3e98ed801937acc3d8f77580686

libs/x-content/licenses/jackson-dataformat-smile-2.8.11.jar.sha1

@@ -0,0 +1 @@
+d9d1c49c5d9d5e46e2aee55f3cdd119286fe0fc1

libs/x-content/licenses/jackson-dataformat-yaml-2.8.10.jar.sha1

@@ -1 +0,0 @@
-1e08caf1d787c825307d8cc6362452086020d853

libs/x-content/licenses/jackson-dataformat-yaml-2.8.11.jar.sha1

@@ -0,0 +1 @@
+2e77c6ff7342cd61ab1ae7cb14ed16aebfc8a72a

modules/lang-painless/src/main/java/org/elasticsearch/painless/Def.java

@@ -279,10 +279,6 @@ public final class Def {
                  String type = signature.substring(1, separator);
                  String call = signature.substring(separator+1, separator2);
                  int numCaptures = Integer.parseInt(signature.substring(separator2+1));
-                 Class<?> captures[] = new Class<?>[numCaptures];
-                 for (int capture = 0; capture < captures.length; capture++) {
-                     captures[capture] = callSiteType.parameterType(i + 1 + capture);
-                 }
                  MethodHandle filter;
                  Class<?> interfaceType = method.typeParameters.get(i - 1 - replaced);
                  if (signature.charAt(0) == 'S') {
@@ -294,11 +290,15 @@ public final class Def {
                                                       interfaceType,
                                                       type,
                                                       call,
-                                                      captures);
+                                                      numCaptures);
                  } else if (signature.charAt(0) == 'D') {
                      // the interface type is now known, but we need to get the implementation.
                      // this is dynamically based on the receiver type (and cached separately, underneath
                      // this cache). It won't blow up since we never nest here (just references)
+                     Class<?> captures[] = new Class<?>[numCaptures];
+                     for (int capture = 0; capture < captures.length; capture++) {
+                         captures[capture] = callSiteType.parameterType(i + 1 + capture);
+                     }
                      MethodType nestedType = MethodType.methodType(interfaceType, captures);
                      CallSite nested = DefBootstrap.bootstrap(painlessLookup,
                                                               localMethods,
@@ -331,57 +331,34 @@ public final class Def {
       */
     static MethodHandle lookupReference(PainlessLookup painlessLookup, Map<String, LocalMethod> localMethods,
             MethodHandles.Lookup methodHandlesLookup, String interfaceClass, Class<?> receiverClass, String name) throws Throwable {
-         Class<?> interfaceType = painlessLookup.canonicalTypeNameToType(interfaceClass);
-         PainlessMethod interfaceMethod = painlessLookup.lookupPainlessClass(interfaceType).functionalMethod;
-         if (interfaceMethod == null) {
-             throw new IllegalArgumentException("Class [" + interfaceClass + "] is not a functional interface");
-         }
-         int arity = interfaceMethod.typeParameters.size();
-         PainlessMethod implMethod = lookupMethodInternal(painlessLookup, receiverClass, name, arity);
+        Class<?> interfaceType = painlessLookup.canonicalTypeNameToType(interfaceClass);
+        PainlessMethod interfaceMethod = painlessLookup.lookupFunctionalInterfacePainlessMethod(interfaceType);
+        if (interfaceMethod == null) {
+            throw new IllegalArgumentException("Class [" + interfaceClass + "] is not a functional interface");
+        }
+        int arity = interfaceMethod.typeParameters.size();
+        PainlessMethod implMethod = lookupMethodInternal(painlessLookup, receiverClass, name, arity);
         return lookupReferenceInternal(painlessLookup, localMethods, methodHandlesLookup,
                 interfaceType, PainlessLookupUtility.typeToCanonicalTypeName(implMethod.targetClass),
-                implMethod.javaMethod.getName(), receiverClass);
+                implMethod.javaMethod.getName(), 1);
      }
 
      /** Returns a method handle to an implementation of clazz, given method reference signature. */
     private static MethodHandle lookupReferenceInternal(PainlessLookup painlessLookup, Map<String, LocalMethod> localMethods,
-            MethodHandles.Lookup methodHandlesLookup, Class<?> clazz, String type, String call, Class<?>... captures) throws Throwable {
-         final FunctionRef ref;
-         if ("this".equals(type)) {
-             // user written method
-             PainlessMethod interfaceMethod = painlessLookup.lookupPainlessClass(clazz).functionalMethod;
-             if (interfaceMethod == null) {
-                 throw new IllegalArgumentException("Cannot convert function reference [" + type + "::" + call + "] " +
-                         "to [" + PainlessLookupUtility.typeToCanonicalTypeName(clazz) + "], not a functional interface");
-             }
-             int arity = interfaceMethod.typeParameters.size() + captures.length;
-             LocalMethod localMethod = localMethods.get(Locals.buildLocalMethodKey(call, arity));
-             if (localMethod == null) {
-                 // is it a synthetic method? If we generated the method ourselves, be more helpful. It can only fail
-                 // because the arity does not match the expected interface type.
-                 if (call.contains("$")) {
-                     throw new IllegalArgumentException("Incorrect number of parameters for [" + interfaceMethod.javaMethod.getName() +
-                                                        "] in [" + clazz + "]");
-                 }
-                 throw new IllegalArgumentException("Unknown call [" + call + "] with [" + arity + "] arguments.");
-             }
-             ref = new FunctionRef(clazz, interfaceMethod, call, localMethod.methodType, captures.length);
-         } else {
-             // whitelist lookup
-             ref = FunctionRef.resolveFromLookup(painlessLookup, clazz, type, call, captures.length);
-         }
-         final CallSite callSite = LambdaBootstrap.lambdaBootstrap(
-             methodHandlesLookup,
-             ref.interfaceMethodName,
-             ref.factoryMethodType,
-             ref.interfaceMethodType,
-             ref.delegateClassName,
-             ref.delegateInvokeType,
-             ref.delegateMethodName,
-             ref.delegateMethodType,
-             ref.isDelegateInterface ? 1 : 0
-         );
-         return callSite.dynamicInvoker().asType(MethodType.methodType(clazz, captures));
+            MethodHandles.Lookup methodHandlesLookup, Class<?> clazz, String type, String call, int captures) throws Throwable {
+        final FunctionRef ref = FunctionRef.create(painlessLookup, localMethods, null, clazz, type, call, captures);
+        final CallSite callSite = LambdaBootstrap.lambdaBootstrap(
+            methodHandlesLookup,
+            ref.interfaceMethodName,
+            ref.factoryMethodType,
+            ref.interfaceMethodType,
+            ref.delegateClassName,
+            ref.delegateInvokeType,
+            ref.delegateMethodName,
+            ref.delegateMethodType,
+            ref.isDelegateInterface ? 1 : 0
+        );
+        return callSite.dynamicInvoker().asType(MethodType.methodType(clazz, ref.factoryMethodType.parameterArray()));
      }
 
     /**

modules/lang-painless/src/main/java/org/elasticsearch/painless/FunctionRef.java

@@ -20,17 +20,17 @@
 package org.elasticsearch.painless;
 
 import org.elasticsearch.painless.Locals.LocalMethod;
-import org.elasticsearch.painless.lookup.PainlessClass;
 import org.elasticsearch.painless.lookup.PainlessConstructor;
 import org.elasticsearch.painless.lookup.PainlessLookup;
 import org.elasticsearch.painless.lookup.PainlessLookupUtility;
 import org.elasticsearch.painless.lookup.PainlessMethod;
-import org.objectweb.asm.Type;
 
 import java.lang.invoke.MethodType;
-import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
+import java.util.Objects;
 
 import static org.elasticsearch.painless.WriterConstants.CLASS_NAME;
 import static org.objectweb.asm.Opcodes.H_INVOKEINTERFACE;
@@ -39,251 +39,210 @@ import static org.objectweb.asm.Opcodes.H_INVOKEVIRTUAL;
 import static org.objectweb.asm.Opcodes.H_NEWINVOKESPECIAL;
 
 /**
- * Reference to a function or lambda.
- * <p>
- * Once you have created one of these, you have "everything you need" to call {@link LambdaBootstrap}
- * either statically from bytecode with invokedynamic, or at runtime from Java.
+ * Contains all the values necessary to write the instruction to initiate a
+ * {@link LambdaBootstrap} for either a function reference or a user-defined
+ * lambda function.
  */
 public class FunctionRef {
 
+    /**
+     * Creates a new FunctionRef which will resolve {@code type::call} from the whitelist.
+     * @param painlessLookup the whitelist against which this script is being compiled
+     * @param localMethods user-defined and synthetic methods generated directly on the script class
+     * @param location the character number within the script at compile-time
+     * @param targetClass functional interface type to implement.
+     * @param typeName the left hand side of a method reference expression
+     * @param methodName the right hand side of a method reference expression
+     * @param numberOfCaptures number of captured arguments
+     */
+    public static FunctionRef create(PainlessLookup painlessLookup, Map<String, LocalMethod> localMethods, Location location,
+            Class<?> targetClass, String typeName, String methodName, int numberOfCaptures) {
+
+        Objects.requireNonNull(painlessLookup);
+        Objects.requireNonNull(targetClass);
+        Objects.requireNonNull(typeName);
+        Objects.requireNonNull(methodName);
+
+        String targetClassName = PainlessLookupUtility.typeToCanonicalTypeName(targetClass);
+        PainlessMethod interfaceMethod;
+
+        try {
+            try {
+                interfaceMethod = painlessLookup.lookupFunctionalInterfacePainlessMethod(targetClass);
+            } catch (IllegalArgumentException iae) {
+                throw new IllegalArgumentException("cannot convert function reference [" + typeName + "::" + methodName + "] " +
+                        "to a non-functional interface [" + targetClassName + "]", iae);
+            }
+
+            String interfaceMethodName = interfaceMethod.javaMethod.getName();
+            MethodType interfaceMethodType = interfaceMethod.methodType.dropParameterTypes(0, 1);
+            String delegateClassName;
+            boolean isDelegateInterface;
+            int delegateInvokeType;
+            String delegateMethodName;
+            MethodType delegateMethodType;
+
+            Class<?> delegateMethodReturnType;
+            List<Class<?>> delegateMethodParameters;
+            int interfaceTypeParametersSize = interfaceMethod.typeParameters.size();
+
+            if ("this".equals(typeName)) {
+                Objects.requireNonNull(localMethods);
+
+                if (numberOfCaptures < 0) {
+                    throw new IllegalStateException("internal error");
+                }
+
+                String localMethodKey = Locals.buildLocalMethodKey(methodName, numberOfCaptures + interfaceTypeParametersSize);
+                LocalMethod localMethod = localMethods.get(localMethodKey);
+
+                if (localMethod == null) {
+                    throw new IllegalArgumentException("function reference [this::" + localMethodKey + "] " +
+                            "matching [" + targetClassName + ", " + interfaceMethodName + "/" + interfaceTypeParametersSize + "] " +
+                            "not found" + (localMethodKey.contains("$") ? " due to an incorrect number of arguments" : "")
+                    );
+                }
+
+                delegateClassName = CLASS_NAME;
+                isDelegateInterface = false;
+                delegateInvokeType = H_INVOKESTATIC;
+                delegateMethodName = localMethod.name;
+                delegateMethodType = localMethod.methodType;
+
+                delegateMethodReturnType = localMethod.returnType;
+                delegateMethodParameters = localMethod.typeParameters;
+            } else if ("new".equals(methodName)) {
+                if (numberOfCaptures != 0) {
+                    throw new IllegalStateException("internal error");
+                }
+
+                PainlessConstructor painlessConstructor;
+
+                try {
+                    painlessConstructor = painlessLookup.lookupPainlessConstructor(typeName, interfaceTypeParametersSize);
+                } catch (IllegalArgumentException iae) {
+                    throw new IllegalArgumentException("function reference [" + typeName + "::new/" + interfaceTypeParametersSize + "] " +
+                            "matching [" + targetClassName + ", " + interfaceMethodName + "/" + interfaceTypeParametersSize + "] " +
+                            "not found", iae);
+                }
+
+                delegateClassName = painlessConstructor.javaConstructor.getDeclaringClass().getName();
+                isDelegateInterface = false;
+                delegateInvokeType = H_NEWINVOKESPECIAL;
+                delegateMethodName = PainlessLookupUtility.CONSTRUCTOR_NAME;
+                delegateMethodType = painlessConstructor.methodType;
+
+                delegateMethodReturnType = painlessConstructor.javaConstructor.getDeclaringClass();
+                delegateMethodParameters = painlessConstructor.typeParameters;
+            } else {
+                if (numberOfCaptures != 0 && numberOfCaptures != 1) {
+                    throw new IllegalStateException("internal error");
+                }
+
+                boolean captured = numberOfCaptures == 1;
+                PainlessMethod painlessMethod;
+
+                try {
+                    painlessMethod = painlessLookup.lookupPainlessMethod(typeName, true, methodName, interfaceTypeParametersSize);
+
+                    if (captured) {
+                        throw new IllegalStateException("internal error");
+                    }
+                } catch (IllegalArgumentException staticIAE) {
+                    try {
+                        painlessMethod = painlessLookup.lookupPainlessMethod(typeName, false, methodName,
+                                captured ? interfaceTypeParametersSize : interfaceTypeParametersSize - 1);
+                    } catch (IllegalArgumentException iae) {
+                        throw new IllegalArgumentException(
+                                "function reference " + "[" + typeName + "::" + methodName + "/" + interfaceTypeParametersSize + "] " +
+                                "matching [" + targetClassName + ", " + interfaceMethodName + "/" + interfaceTypeParametersSize + "] " +
+                                "not found", iae);
+                    }
+                }
+
+                delegateClassName = painlessMethod.javaMethod.getDeclaringClass().getName();
+                isDelegateInterface = painlessMethod.javaMethod.getDeclaringClass().isInterface();
+
+                if (Modifier.isStatic(painlessMethod.javaMethod.getModifiers())) {
+                    delegateInvokeType = H_INVOKESTATIC;
+                } else if (isDelegateInterface) {
+                    delegateInvokeType = H_INVOKEINTERFACE;
+                } else {
+                    delegateInvokeType = H_INVOKEVIRTUAL;
+                }
+
+                delegateMethodName = painlessMethod.javaMethod.getName();
+                delegateMethodType = painlessMethod.methodType;
+
+                delegateMethodReturnType = painlessMethod.returnType;
+
+                if (delegateMethodType.parameterList().size() > painlessMethod.typeParameters.size()) {
+                    delegateMethodParameters = new ArrayList<>(painlessMethod.typeParameters);
+                    delegateMethodParameters.add(0, delegateMethodType.parameterType(0));
+                } else {
+                    delegateMethodParameters = painlessMethod.typeParameters;
+                }
+            }
+
+            if (location != null) {
+                for (int typeParameter = 0; typeParameter < interfaceTypeParametersSize; ++typeParameter) {
+                    Class<?> from = interfaceMethod.typeParameters.get(typeParameter);
+                    Class<?> to = delegateMethodParameters.get(numberOfCaptures + typeParameter);
+                    AnalyzerCaster.getLegalCast(location, from, to, false, true);
+                }
+
+                if (interfaceMethod.returnType != void.class) {
+                    AnalyzerCaster.getLegalCast(location, delegateMethodReturnType, interfaceMethod.returnType, false, true);
+                }
+            }
+
+            MethodType factoryMethodType = MethodType.methodType(targetClass,
+                    delegateMethodType.dropParameterTypes(numberOfCaptures, delegateMethodType.parameterCount()));
+            delegateMethodType = delegateMethodType.dropParameterTypes(0, numberOfCaptures);
+
+            return new FunctionRef(interfaceMethodName, interfaceMethodType,
+                    delegateClassName, isDelegateInterface, delegateInvokeType, delegateMethodName, delegateMethodType,
+                    factoryMethodType
+            );
+        } catch (IllegalArgumentException iae) {
+            if (location != null) {
+                throw location.createError(iae);
+            }
+
+            throw iae;
+        }
+    }
+
     /** functional interface method name */
     public final String interfaceMethodName;
-    /** factory (CallSite) method signature */
-    public final MethodType factoryMethodType;
     /** functional interface method signature */
     public final MethodType interfaceMethodType;
     /** class of the delegate method to be called */
     public final String delegateClassName;
+    /** whether a call is made on a delegate interface */
+    public final boolean isDelegateInterface;
     /** the invocation type of the delegate method */
     public final int delegateInvokeType;
     /** the name of the delegate method */
     public final String delegateMethodName;
     /** delegate method signature */
     public final MethodType delegateMethodType;
+    /** factory (CallSite) method signature */
+    public final MethodType factoryMethodType;
 
-    /** interface method */
-    public final PainlessMethod interfaceMethod;
-    /** delegate method type parameters */
-    public final List<Class<?>> delegateTypeParameters;
-    /** delegate method return type */
-    public final Class<?> delegateReturnType;
+    private FunctionRef(
+            String interfaceMethodName, MethodType interfaceMethodType,
+            String delegateClassName, boolean isDelegateInterface,
+            int delegateInvokeType, String delegateMethodName, MethodType delegateMethodType,
+            MethodType factoryMethodType) {
 
-    /** factory method type descriptor */
-    public final String factoryDescriptor;
-    /** functional interface method as type */
-    public final Type interfaceType;
-    /** delegate method type method as type */
-    public final Type delegateType;
-
-    /** whether a call is made on a delegate interface */
-    public final boolean isDelegateInterface;
-
-    /**
-     * Creates a new FunctionRef, which will resolve {@code type::call} from the whitelist.
-     * @param painlessLookup the whitelist against which this script is being compiled
-     * @param expected functional interface type to implement.
-     * @param type the left hand side of a method reference expression
-     * @param call the right hand side of a method reference expression
-     * @param numCaptures number of captured arguments
-     */
-    public static FunctionRef resolveFromLookup(
-            PainlessLookup painlessLookup, Class<?> expected, String type, String call, int numCaptures) {
-
-        if ("new".equals(call)) {
-            return new FunctionRef(expected, painlessLookup.lookupPainlessClass(expected).functionalMethod,
-                    lookup(painlessLookup, expected, type), numCaptures);
-        } else {
-            return new FunctionRef(expected, painlessLookup.lookupPainlessClass(expected).functionalMethod,
-                    lookup(painlessLookup, expected, type, call, numCaptures > 0), numCaptures);
-        }
-    }
-
-    /**
-     * Creates a new FunctionRef (already resolved)
-     * @param expected functional interface type to implement
-     * @param interfaceMethod functional interface method
-     * @param delegateConstructor implementation constructor
-     * @param numCaptures number of captured arguments
-     */
-    public FunctionRef(Class<?> expected, PainlessMethod interfaceMethod, PainlessConstructor delegateConstructor, int numCaptures) {
-        Constructor<?> javaConstructor = delegateConstructor.javaConstructor;
-        MethodType delegateMethodType = delegateConstructor.methodType;
-
-        this.interfaceMethodName = interfaceMethod.javaMethod.getName();
-        this.factoryMethodType = MethodType.methodType(expected,
-                delegateMethodType.dropParameterTypes(numCaptures, delegateMethodType.parameterCount()));
-        this.interfaceMethodType = interfaceMethod.methodType.dropParameterTypes(0, 1);
-
-        this.delegateClassName = javaConstructor.getDeclaringClass().getName();
-        this.isDelegateInterface = false;
-        this.delegateInvokeType = H_NEWINVOKESPECIAL;
-        this.delegateMethodName = PainlessLookupUtility.CONSTRUCTOR_NAME;
-        this.delegateMethodType = delegateMethodType.dropParameterTypes(0, numCaptures);
-
-        this.interfaceMethod = interfaceMethod;
-        this.delegateTypeParameters = delegateConstructor.typeParameters;
-        this.delegateReturnType = void.class;
-
-        this.factoryDescriptor = factoryMethodType.toMethodDescriptorString();
-        this.interfaceType = Type.getMethodType(interfaceMethodType.toMethodDescriptorString());
-        this.delegateType = Type.getMethodType(this.delegateMethodType.toMethodDescriptorString());
-    }
-
-    /**
-     * Creates a new FunctionRef (already resolved)
-     * @param expected functional interface type to implement
-     * @param interfaceMethod functional interface method
-     * @param delegateMethod implementation method
-     * @param numCaptures number of captured arguments
-     */
-    public FunctionRef(Class<?> expected, PainlessMethod interfaceMethod, PainlessMethod delegateMethod, int numCaptures) {
-        MethodType delegateMethodType = delegateMethod.methodType;
-
-        this.interfaceMethodName = interfaceMethod.javaMethod.getName();
-        this.factoryMethodType = MethodType.methodType(expected,
-                delegateMethodType.dropParameterTypes(numCaptures, delegateMethodType.parameterCount()));
-        this.interfaceMethodType = interfaceMethod.methodType.dropParameterTypes(0, 1);
-
-        this.delegateClassName = delegateMethod.javaMethod.getDeclaringClass().getName();
-        this.isDelegateInterface = delegateMethod.javaMethod.getDeclaringClass().isInterface();
-
-        if (Modifier.isStatic(delegateMethod.javaMethod.getModifiers())) {
-            this.delegateInvokeType = H_INVOKESTATIC;
-        } else if (delegateMethod.javaMethod.getDeclaringClass().isInterface()) {
-            this.delegateInvokeType = H_INVOKEINTERFACE;
-        } else {
-            this.delegateInvokeType = H_INVOKEVIRTUAL;
-        }
-
-        this.delegateMethodName = delegateMethod.javaMethod.getName();
-        this.delegateMethodType = delegateMethodType.dropParameterTypes(0, numCaptures);
-
-        this.interfaceMethod = interfaceMethod;
-        this.delegateTypeParameters = delegateMethod.typeParameters;
-        this.delegateReturnType = delegateMethod.returnType;
-
-        this.factoryDescriptor = factoryMethodType.toMethodDescriptorString();
-        this.interfaceType = Type.getMethodType(interfaceMethodType.toMethodDescriptorString());
-        this.delegateType = Type.getMethodType(this.delegateMethodType.toMethodDescriptorString());
-    }
-
-    /**
-     * Creates a new FunctionRef (already resolved)
-     * @param expected functional interface type to implement
-     * @param interfaceMethod functional interface method
-     * @param delegateMethod implementation method
-     * @param numCaptures number of captured arguments
-     */
-    public FunctionRef(Class<?> expected, PainlessMethod interfaceMethod, LocalMethod delegateMethod, int numCaptures) {
-        MethodType delegateMethodType = delegateMethod.methodType;
-
-        this.interfaceMethodName = interfaceMethod.javaMethod.getName();
-        this.factoryMethodType = MethodType.methodType(expected,
-                delegateMethodType.dropParameterTypes(numCaptures, delegateMethodType.parameterCount()));
-        this.interfaceMethodType = interfaceMethod.methodType.dropParameterTypes(0, 1);
-
-        this.delegateClassName = CLASS_NAME;
-        this.isDelegateInterface = false;
-        this.delegateInvokeType = H_INVOKESTATIC;
-
-        this.delegateMethodName = delegateMethod.name;
-        this.delegateMethodType = delegateMethodType.dropParameterTypes(0, numCaptures);
-
-        this.interfaceMethod = interfaceMethod;
-        this.delegateTypeParameters = delegateMethod.typeParameters;
-        this.delegateReturnType = delegateMethod.returnType;
-
-        this.factoryDescriptor = factoryMethodType.toMethodDescriptorString();
-        this.interfaceType = Type.getMethodType(interfaceMethodType.toMethodDescriptorString());
-        this.delegateType = Type.getMethodType(this.delegateMethodType.toMethodDescriptorString());
-    }
-
-    /**
-     * Creates a new FunctionRef (low level).
-     * It is for runtime use only.
-     */
-    public FunctionRef(Class<?> expected,
-                       PainlessMethod interfaceMethod, String delegateMethodName, MethodType delegateMethodType, int numCaptures) {
-        this.interfaceMethodName = interfaceMethod.javaMethod.getName();
-        this.factoryMethodType = MethodType.methodType(expected,
-            delegateMethodType.dropParameterTypes(numCaptures, delegateMethodType.parameterCount()));
-        this.interfaceMethodType = interfaceMethod.methodType.dropParameterTypes(0, 1);
-
-        this.delegateClassName = CLASS_NAME;
-        this.delegateInvokeType = H_INVOKESTATIC;
+        this.interfaceMethodName = interfaceMethodName;
+        this.interfaceMethodType = interfaceMethodType;
+        this.delegateClassName = delegateClassName;
+        this.isDelegateInterface = isDelegateInterface;
+        this.delegateInvokeType = delegateInvokeType;
         this.delegateMethodName = delegateMethodName;
-        this.delegateMethodType = delegateMethodType.dropParameterTypes(0, numCaptures);
-        this.isDelegateInterface = false;
-
-        this.interfaceMethod = null;
-        this.delegateTypeParameters = null;
-        this.delegateReturnType = null;
-
-        this.factoryDescriptor = null;
-        this.interfaceType = null;
-        this.delegateType = null;
-    }
-
-    /**
-     * Looks up {@code type} from the whitelist, and returns a matching constructor.
-     */
-    private static PainlessConstructor lookup(PainlessLookup painlessLookup, Class<?> expected, String type) {
-        // check its really a functional interface
-        // for e.g. Comparable
-        PainlessMethod method = painlessLookup.lookupPainlessClass(expected).functionalMethod;
-        if (method == null) {
-            throw new IllegalArgumentException("Cannot convert function reference [" + type + "::new] " +
-                    "to [" + PainlessLookupUtility.typeToCanonicalTypeName(expected) + "], not a functional interface");
-        }
-
-        // lookup requested constructor
-        PainlessClass struct = painlessLookup.lookupPainlessClass(painlessLookup.canonicalTypeNameToType(type));
-        PainlessConstructor impl = struct.constructors.get(PainlessLookupUtility.buildPainlessConstructorKey(method.typeParameters.size()));
-
-        if (impl == null) {
-            throw new IllegalArgumentException("Unknown reference [" + type + "::new] matching [" + expected + "]");
-        }
-
-        return impl;
-    }
-
-    /**
-     * Looks up {@code type::call} from the whitelist, and returns a matching method.
-     */
-    private static PainlessMethod lookup(PainlessLookup painlessLookup, Class<?> expected,
-                                         String type, String call, boolean receiverCaptured) {
-        // check its really a functional interface
-        // for e.g. Comparable
-        PainlessMethod method = painlessLookup.lookupPainlessClass(expected).functionalMethod;
-        if (method == null) {
-            throw new IllegalArgumentException("Cannot convert function reference [" + type + "::" + call + "] " +
-                    "to [" + PainlessLookupUtility.typeToCanonicalTypeName(expected) + "], not a functional interface");
-        }
-
-        // lookup requested method
-        PainlessClass struct = painlessLookup.lookupPainlessClass(painlessLookup.canonicalTypeNameToType(type));
-        final PainlessMethod impl;
-        // look for a static impl first
-        PainlessMethod staticImpl =
-                struct.staticMethods.get(PainlessLookupUtility.buildPainlessMethodKey(call, method.typeParameters.size()));
-        if (staticImpl == null) {
-            // otherwise a virtual impl
-            final int arity;
-            if (receiverCaptured) {
-                // receiver captured
-                arity = method.typeParameters.size();
-            } else {
-                // receiver passed
-                arity = method.typeParameters.size() - 1;
-            }
-            impl = struct.methods.get(PainlessLookupUtility.buildPainlessMethodKey(call, arity));
-        } else {
-            impl = staticImpl;
-        }
-        if (impl == null) {
-            throw new IllegalArgumentException("Unknown reference [" + type + "::" + call + "] matching " +
-                                               "[" + expected + "]");
-        }
-        return impl;
+        this.delegateMethodType = delegateMethodType;
+        this.factoryMethodType = factoryMethodType;
     }
 }

modules/lang-painless/src/main/java/org/elasticsearch/painless/MethodWriter.java

@@ -56,6 +56,7 @@ import static org.elasticsearch.painless.WriterConstants.DEF_TO_SHORT_EXPLICIT;
 import static org.elasticsearch.painless.WriterConstants.DEF_TO_SHORT_IMPLICIT;
 import static org.elasticsearch.painless.WriterConstants.DEF_UTIL_TYPE;
 import static org.elasticsearch.painless.WriterConstants.INDY_STRING_CONCAT_BOOTSTRAP_HANDLE;
+import static org.elasticsearch.painless.WriterConstants.LAMBDA_BOOTSTRAP_HANDLE;
 import static org.elasticsearch.painless.WriterConstants.MAX_INDY_STRING_CONCAT_ARGS;
 import static org.elasticsearch.painless.WriterConstants.PAINLESS_ERROR_TYPE;
 import static org.elasticsearch.painless.WriterConstants.STRINGBUILDER_APPEND_BOOLEAN;
@@ -439,4 +440,18 @@ public final class MethodWriter extends GeneratorAdapter {
             invokeVirtual(type, method);
         }
     }
+
+    public void invokeLambdaCall(FunctionRef functionRef) {
+        invokeDynamic(
+                functionRef.interfaceMethodName,
+                functionRef.factoryMethodType.toMethodDescriptorString(),
+                LAMBDA_BOOTSTRAP_HANDLE,
+                Type.getMethodType(functionRef.interfaceMethodType.toMethodDescriptorString()),
+                functionRef.delegateClassName,
+                functionRef.delegateInvokeType,
+                functionRef.delegateMethodName,
+                Type.getMethodType(functionRef.delegateMethodType.toMethodDescriptorString()),
+                functionRef.isDelegateInterface ? 1 : 0
+        );
+    }
 }

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessClass.java

@@ -35,13 +35,13 @@ public final class PainlessClass {
     public final Map<String, MethodHandle> getterMethodHandles;
     public final Map<String, MethodHandle> setterMethodHandles;
 
-    public final PainlessMethod functionalMethod;
+    public final PainlessMethod functionalInterfaceMethod;
 
     PainlessClass(Map<String, PainlessConstructor> constructors,
             Map<String, PainlessMethod> staticMethods, Map<String, PainlessMethod> methods,
             Map<String, PainlessField> staticFields, Map<String, PainlessField> fields,
             Map<String, MethodHandle> getterMethodHandles, Map<String, MethodHandle> setterMethodHandles,
-            PainlessMethod functionalMethod) {
+            PainlessMethod functionalInterfaceMethod) {
 
         this.constructors = Collections.unmodifiableMap(constructors);
 
@@ -54,6 +54,6 @@ public final class PainlessClass {
         this.getterMethodHandles = Collections.unmodifiableMap(getterMethodHandles);
         this.setterMethodHandles = Collections.unmodifiableMap(setterMethodHandles);
 
-        this.functionalMethod = functionalMethod;
+        this.functionalInterfaceMethod = functionalInterfaceMethod;
     }
 }

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessClassBuilder.java

@@ -35,7 +35,7 @@ final class PainlessClassBuilder {
     final Map<String, MethodHandle> getterMethodHandles;
     final Map<String, MethodHandle> setterMethodHandles;
 
-    PainlessMethod functionalMethod;
+    PainlessMethod functionalInterfaceMethod;
 
     PainlessClassBuilder() {
         constructors = new HashMap<>();
@@ -49,11 +49,11 @@ final class PainlessClassBuilder {
         getterMethodHandles = new HashMap<>();
         setterMethodHandles = new HashMap<>();
 
-        functionalMethod = null;
+        functionalInterfaceMethod = null;
     }
 
     PainlessClass build() {
         return new PainlessClass(constructors, staticMethods, methods, staticFields, fields,
-                getterMethodHandles, setterMethodHandles, functionalMethod);
+                getterMethodHandles, setterMethodHandles, functionalInterfaceMethod);
     }
 }

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessLookup.java

@@ -62,6 +62,14 @@ public final class PainlessLookup {
         return classesToPainlessClasses.get(targetClass);
     }
 
+    public PainlessConstructor lookupPainlessConstructor(String targetClassName, int constructorArity) {
+        Objects.requireNonNull(targetClassName);
+
+        Class<?> targetClass = canonicalTypeNameToType(targetClassName);
+
+        return lookupPainlessConstructor(targetClass, constructorArity);
+    }
+
     public PainlessConstructor lookupPainlessConstructor(Class<?> targetClass, int constructorArity) {
         Objects.requireNonNull(targetClass);
 
@@ -83,6 +91,14 @@ public final class PainlessLookup {
         return painlessConstructor;
     }
 
+    public PainlessMethod lookupPainlessMethod(String targetClassName, boolean isStatic, String methodName, int methodArity) {
+        Objects.requireNonNull(targetClassName);
+
+        Class<?> targetClass = canonicalTypeNameToType(targetClassName);
+
+        return lookupPainlessMethod(targetClass, isStatic, methodName, methodArity);
+    }
+
     public PainlessMethod lookupPainlessMethod(Class<?> targetClass, boolean isStatic, String methodName, int methodArity) {
         Objects.requireNonNull(targetClass);
         Objects.requireNonNull(methodName);
@@ -111,6 +127,14 @@ public final class PainlessLookup {
         return painlessMethod;
     }
 
+    public PainlessField lookupPainlessField(String targetClassName, boolean isStatic, String fieldName) {
+        Objects.requireNonNull(targetClassName);
+
+        Class<?> targetClass = canonicalTypeNameToType(targetClassName);
+
+        return lookupPainlessField(targetClass, isStatic, fieldName);
+    }
+
     public PainlessField lookupPainlessField(Class<?> targetClass, boolean isStatic, String fieldName) {
         Objects.requireNonNull(targetClass);
         Objects.requireNonNull(fieldName);
@@ -134,4 +158,20 @@ public final class PainlessLookup {
 
         return painlessField;
     }
+
+    public PainlessMethod lookupFunctionalInterfacePainlessMethod(Class<?> targetClass) {
+        PainlessClass targetPainlessClass = classesToPainlessClasses.get(targetClass);
+
+        if (targetPainlessClass == null) {
+            throw new IllegalArgumentException("target class [" + typeToCanonicalTypeName(targetClass) + "] not found");
+        }
+
+        PainlessMethod functionalInterfacePainlessMethod = targetPainlessClass.functionalInterfaceMethod;
+
+        if (functionalInterfacePainlessMethod == null) {
+            throw new IllegalArgumentException("target class [" + typeToCanonicalTypeName(targetClass) + "] is not a functional interface");
+        }
+
+        return functionalInterfacePainlessMethod;
+    }
 }

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessLookupBuilder.java

@@ -875,7 +875,7 @@ public final class PainlessLookupBuilder {
             } else if (javaMethods.size() == 1) {
                 java.lang.reflect.Method javaMethod = javaMethods.get(0);
                 String painlessMethodKey = buildPainlessMethodKey(javaMethod.getName(), javaMethod.getParameterCount());
-                painlessClassBuilder.functionalMethod = painlessClassBuilder.methods.get(painlessMethodKey);
+                painlessClassBuilder.functionalInterfaceMethod = painlessClassBuilder.methods.get(painlessMethodKey);
             }
         }
     }

modules/lang-painless/src/main/java/org/elasticsearch/painless/node/ECapturingFunctionRef.java

@@ -19,7 +19,6 @@
 
 package org.elasticsearch.painless.node;
 
-import org.elasticsearch.painless.AnalyzerCaster;
 import org.elasticsearch.painless.DefBootstrap;
 import org.elasticsearch.painless.FunctionRef;
 import org.elasticsearch.painless.Globals;
@@ -35,8 +34,6 @@ import org.objectweb.asm.Type;
 import java.util.Objects;
 import java.util.Set;
 
-import static org.elasticsearch.painless.WriterConstants.LAMBDA_BOOTSTRAP_HANDLE;
-
 /**
  * Represents a capturing function reference.
  */
@@ -76,23 +73,8 @@ public final class ECapturingFunctionRef extends AExpression implements ILambda
             defPointer = null;
             // static case
             if (captured.clazz != def.class) {
-                try {
-                    ref = FunctionRef.resolveFromLookup(locals.getPainlessLookup(), expected,
-                            PainlessLookupUtility.typeToCanonicalTypeName(captured.clazz), call, 1);
-
-                    // check casts between the interface method and the delegate method are legal
-                    for (int i = 0; i < ref.interfaceMethod.typeParameters.size(); ++i) {
-                        Class<?> from = ref.interfaceMethod.typeParameters.get(i);
-                        Class<?> to = ref.delegateTypeParameters.get(i);
-                        AnalyzerCaster.getLegalCast(location, from, to, false, true);
-                    }
-
-                    if (ref.interfaceMethod.returnType != void.class) {
-                        AnalyzerCaster.getLegalCast(location, ref.delegateReturnType, ref.interfaceMethod.returnType, false, true);
-                    }
-                } catch (IllegalArgumentException e) {
-                    throw createError(e);
-                }
+                ref = FunctionRef.create(locals.getPainlessLookup(), locals.getMethods(), location,
+                        expected, PainlessLookupUtility.typeToCanonicalTypeName(captured.clazz), call, 1);
             }
             actual = expected;
         }
@@ -114,17 +96,7 @@ public final class ECapturingFunctionRef extends AExpression implements ILambda
         } else {
             // typed interface, typed implementation
             writer.visitVarInsn(MethodWriter.getType(captured.clazz).getOpcode(Opcodes.ILOAD), captured.getSlot());
-            writer.invokeDynamic(
-                ref.interfaceMethodName,
-                ref.factoryDescriptor,
-                LAMBDA_BOOTSTRAP_HANDLE,
-                ref.interfaceType,
-                ref.delegateClassName,
-                ref.delegateInvokeType,
-                ref.delegateMethodName,
-                ref.delegateType,
-                ref.isDelegateInterface ? 1 : 0
-            );
+            writer.invokeLambdaCall(ref);
         }
     }
 

modules/lang-painless/src/main/java/org/elasticsearch/painless/node/EFunctionRef.java

@@ -19,22 +19,16 @@
 
 package org.elasticsearch.painless.node;
 
-import org.elasticsearch.painless.AnalyzerCaster;
 import org.elasticsearch.painless.FunctionRef;
 import org.elasticsearch.painless.Globals;
 import org.elasticsearch.painless.Locals;
-import org.elasticsearch.painless.Locals.LocalMethod;
 import org.elasticsearch.painless.Location;
 import org.elasticsearch.painless.MethodWriter;
-import org.elasticsearch.painless.lookup.PainlessLookupUtility;
-import org.elasticsearch.painless.lookup.PainlessMethod;
 import org.objectweb.asm.Type;
 
 import java.util.Objects;
 import java.util.Set;
 
-import static org.elasticsearch.painless.WriterConstants.LAMBDA_BOOTSTRAP_HANDLE;
-
 /**
  * Represents a function reference.
  */
@@ -63,39 +57,7 @@ public final class EFunctionRef extends AExpression implements ILambda {
             defPointer = "S" + type + "." + call + ",0";
         } else {
             defPointer = null;
-            try {
-                if ("this".equals(type)) {
-                    // user's own function
-                    PainlessMethod interfaceMethod = locals.getPainlessLookup().lookupPainlessClass(expected).functionalMethod;
-                    if (interfaceMethod == null) {
-                        throw new IllegalArgumentException("Cannot convert function reference [" + type + "::" + call + "] " +
-                                "to [" + PainlessLookupUtility.typeToCanonicalTypeName(expected) + "], not a functional interface");
-                    }
-                    LocalMethod delegateMethod = locals.getMethod(call, interfaceMethod.typeParameters.size());
-                    if (delegateMethod == null) {
-                        throw new IllegalArgumentException("Cannot convert function reference [" + type + "::" + call + "] " +
-                                "to [" + PainlessLookupUtility.typeToCanonicalTypeName(expected) + "], function not found");
-                    }
-                    ref = new FunctionRef(expected, interfaceMethod, delegateMethod, 0);
-
-                    // check casts between the interface method and the delegate method are legal
-                    for (int i = 0; i < interfaceMethod.typeParameters.size(); ++i) {
-                        Class<?> from = interfaceMethod.typeParameters.get(i);
-                        Class<?> to = delegateMethod.typeParameters.get(i);
-                        AnalyzerCaster.getLegalCast(location, from, to, false, true);
-                    }
-
-                    if (interfaceMethod.returnType != void.class) {
-                        AnalyzerCaster.getLegalCast(location, delegateMethod.returnType, interfaceMethod.returnType, false, true);
-                    }
-                } else {
-                    // whitelist lookup
-                    ref = FunctionRef.resolveFromLookup(locals.getPainlessLookup(), expected, type, call, 0);
-                }
-
-            } catch (IllegalArgumentException e) {
-                throw createError(e);
-            }
+            ref = FunctionRef.create(locals.getPainlessLookup(), locals.getMethods(), location, expected, type, call, 0);
             actual = expected;
         }
     }
@@ -104,17 +66,7 @@ public final class EFunctionRef extends AExpression implements ILambda {
     void write(MethodWriter writer, Globals globals) {
         if (ref != null) {
             writer.writeDebugInfo(location);
-            writer.invokeDynamic(
-                ref.interfaceMethodName,
-                ref.factoryDescriptor,
-                LAMBDA_BOOTSTRAP_HANDLE,
-                ref.interfaceType,
-                ref.delegateClassName,
-                ref.delegateInvokeType,
-                ref.delegateMethodName,
-                ref.delegateType,
-                ref.isDelegateInterface ? 1 : 0
-            );
+            writer.invokeLambdaCall(ref);
         } else {
             // TODO: don't do this: its just to cutover :)
             writer.push((String)null);

modules/lang-painless/src/main/java/org/elasticsearch/painless/node/ELambda.java

@@ -19,11 +19,9 @@
 
 package org.elasticsearch.painless.node;
 
-import org.elasticsearch.painless.AnalyzerCaster;
 import org.elasticsearch.painless.FunctionRef;
 import org.elasticsearch.painless.Globals;
 import org.elasticsearch.painless.Locals;
-import org.elasticsearch.painless.Locals.LocalMethod;
 import org.elasticsearch.painless.Locals.Variable;
 import org.elasticsearch.painless.Location;
 import org.elasticsearch.painless.MethodWriter;
@@ -40,8 +38,6 @@ import java.util.List;
 import java.util.Objects;
 import java.util.Set;
 
-import static org.elasticsearch.painless.WriterConstants.LAMBDA_BOOTSTRAP_HANDLE;
-
 /**
  * Lambda expression node.
  * <p>
@@ -122,7 +118,7 @@ public final class ELambda extends AExpression implements ILambda {
 
         } else {
             // we know the method statically, infer return type and any unknown/def types
-            interfaceMethod = locals.getPainlessLookup().lookupPainlessClass(expected).functionalMethod;
+            interfaceMethod = locals.getPainlessLookup().lookupFunctionalInterfacePainlessMethod(expected);
             if (interfaceMethod == null) {
                 throw createError(new IllegalArgumentException("Cannot pass lambda to " +
                         "[" + PainlessLookupUtility.typeToCanonicalTypeName(expected) + "], not a functional interface"));
@@ -184,25 +180,8 @@ public final class ELambda extends AExpression implements ILambda {
             defPointer = "Sthis." + name + "," + captures.size();
         } else {
             defPointer = null;
-            try {
-                LocalMethod localMethod =
-                        new LocalMethod(desugared.name, desugared.returnType, desugared.typeParameters, desugared.methodType);
-                ref = new FunctionRef(expected, interfaceMethod, localMethod, captures.size());
-            } catch (IllegalArgumentException e) {
-                throw createError(e);
-            }
-
-            // check casts between the interface method and the delegate method are legal
-            for (int i = 0; i < interfaceMethod.typeParameters.size(); ++i) {
-                Class<?> from = interfaceMethod.typeParameters.get(i);
-                Class<?> to = desugared.parameters.get(i + captures.size()).clazz;
-                AnalyzerCaster.getLegalCast(location, from, to, false, true);
-            }
-
-            if (interfaceMethod.returnType != void.class) {
-                AnalyzerCaster.getLegalCast(location, desugared.returnType, interfaceMethod.returnType, false, true);
-            }
-
+            ref = FunctionRef.create(
+                    locals.getPainlessLookup(), locals.getMethods(), location, expected, "this", desugared.name, captures.size());
             actual = expected;
         }
     }
@@ -218,17 +197,7 @@ public final class ELambda extends AExpression implements ILambda {
                 writer.visitVarInsn(MethodWriter.getType(capture.clazz).getOpcode(Opcodes.ILOAD), capture.getSlot());
             }
 
-            writer.invokeDynamic(
-                ref.interfaceMethodName,
-                ref.factoryDescriptor,
-                LAMBDA_BOOTSTRAP_HANDLE,
-                ref.interfaceType,
-                ref.delegateClassName,
-                ref.delegateInvokeType,
-                ref.delegateMethodName,
-                ref.delegateType,
-                ref.isDelegateInterface ? 1 : 0
-            );
+            writer.invokeLambdaCall(ref);
         } else {
             // placeholder
             writer.push((String)null);

modules/lang-painless/src/test/java/org/elasticsearch/painless/FunctionRefTests.java

@@ -27,7 +27,6 @@ import java.lang.invoke.LambdaConversionException;
 import static java.util.Collections.singletonMap;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.endsWith;
-import static org.hamcrest.Matchers.startsWith;
 
 public class FunctionRefTests extends ScriptTestCase {
 
@@ -193,14 +192,15 @@ public class FunctionRefTests extends ScriptTestCase {
         Exception e = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("List l = [2, 1]; l.sort(Integer::bogus); return l.get(0);");
         });
-        assertThat(e.getMessage(), startsWith("Unknown reference"));
+        assertThat(e.getMessage(), containsString("function reference [Integer::bogus/2] matching [java.util.Comparator"));
     }
 
     public void testQualifiedMethodMissing() {
         Exception e = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("List l = [2, 1]; l.sort(org.joda.time.ReadableDateTime::bogus); return l.get(0);", false);
         });
-        assertThat(e.getMessage(), startsWith("Unknown reference"));
+        assertThat(e.getMessage(),
+                containsString("function reference [org.joda.time.ReadableDateTime::bogus/2] matching [java.util.Comparator"));
     }
 
     public void testClassMissing() {
@@ -223,11 +223,12 @@ public class FunctionRefTests extends ScriptTestCase {
         IllegalArgumentException expected = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("List l = new ArrayList(); l.add(2); l.add(1); l.add(Integer::bogus); return l.get(0);");
         });
-        assertThat(expected.getMessage(), containsString("Cannot convert function reference"));
+        assertThat(expected.getMessage(),
+                containsString("cannot convert function reference [Integer::bogus] to a non-functional interface [def]"));
     }
 
     public void testIncompatible() {
-        expectScriptThrows(BootstrapMethodError.class, () -> {
+        expectScriptThrows(ClassCastException.class, () -> {
             exec("List l = new ArrayList(); l.add(2); l.add(1); l.sort(String::startsWith); return l.get(0);");
         });
     }
@@ -236,28 +237,32 @@ public class FunctionRefTests extends ScriptTestCase {
         IllegalArgumentException expected = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("Optional.empty().orElseGet(String::startsWith);");
         });
-        assertThat(expected.getMessage(), containsString("Unknown reference"));
+        assertThat(expected.getMessage(),
+                containsString("function reference [String::startsWith/0] matching [java.util.function.Supplier"));
     }
 
     public void testWrongArityNotEnough() {
         IllegalArgumentException expected = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("List l = new ArrayList(); l.add(2); l.add(1); l.sort(String::isEmpty);");
         });
-        assertTrue(expected.getMessage().contains("Unknown reference"));
+        assertThat(expected.getMessage(), containsString(
+                "function reference [String::isEmpty/2] matching [java.util.Comparator"));
     }
 
     public void testWrongArityDef() {
         IllegalArgumentException expected = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("def y = Optional.empty(); return y.orElseGet(String::startsWith);");
         });
-        assertThat(expected.getMessage(), containsString("Unknown reference"));
+        assertThat(expected.getMessage(),
+                containsString("function reference [String::startsWith/0] matching [java.util.function.Supplier"));
     }
 
     public void testWrongArityNotEnoughDef() {
         IllegalArgumentException expected = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("def l = new ArrayList(); l.add(2); l.add(1); l.sort(String::isEmpty);");
         });
-        assertThat(expected.getMessage(), containsString("Unknown reference"));
+        assertThat(expected.getMessage(),
+                containsString("function reference [String::isEmpty/2] matching [java.util.Comparator"));
     }
 
     public void testReturnVoid() {

modules/lang-painless/src/test/java/org/elasticsearch/painless/LambdaTests.java

@@ -184,7 +184,7 @@ public class LambdaTests extends ScriptTestCase {
         IllegalArgumentException expected = expectScriptThrows(IllegalArgumentException.class, () -> {
             exec("def y = Optional.empty(); return y.orElseGet(x -> x);");
         });
-        assertTrue(expected.getMessage(), expected.getMessage().contains("Incorrect number of parameters"));
+        assertTrue(expected.getMessage(), expected.getMessage().contains("due to an incorrect number of arguments"));
     }
 
     public void testWrongArityNotEnough() {
@@ -200,7 +200,7 @@ public class LambdaTests extends ScriptTestCase {
             exec("def l = new ArrayList(); l.add(1); l.add(1); "
                + "return l.stream().mapToInt(() -> 5).sum();");
         });
-        assertTrue(expected.getMessage().contains("Incorrect number of parameters"));
+        assertTrue(expected.getMessage(), expected.getMessage().contains("due to an incorrect number of arguments"));
     }
 
     public void testLambdaInFunction() {

modules/percolator/src/main/java/org/elasticsearch/percolator/PercolateQueryBuilder.java

@@ -756,7 +756,7 @@ public class PercolateQueryBuilder extends AbstractQueryBuilder<PercolateQueryBu
             @Override
             @SuppressWarnings("unchecked")
             public <IFD extends IndexFieldData<?>> IFD getForField(MappedFieldType fieldType) {
-                IndexFieldData.Builder builder = fieldType.fielddataBuilder(shardContext.getFullyQualifiedIndexName());
+                IndexFieldData.Builder builder = fieldType.fielddataBuilder(shardContext.getFullyQualifiedIndex().getName());
                 IndexFieldDataCache cache = new IndexFieldDataCache.None();
                 CircuitBreakerService circuitBreaker = new NoneCircuitBreakerService();
                 return (IFD) builder.build(shardContext.getIndexSettings(), fieldType, cache, circuitBreaker,
@@ -764,5 +764,4 @@ public class PercolateQueryBuilder extends AbstractQueryBuilder<PercolateQueryBu
             }
         };
     }
-
 }

modules/transport-netty4/src/test/java/org/elasticsearch/http/netty4/Netty4HttpClient.java

@@ -58,6 +58,7 @@ import java.util.concurrent.TimeUnit;
 
 import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
 import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+import static org.junit.Assert.fail;
 
 /**
  * Tiny helper to send http requests over netty.
@@ -145,7 +146,9 @@ class Netty4HttpClient implements Closeable {
             for (HttpRequest request : requests) {
                 channelFuture.channel().writeAndFlush(request);
             }
-            latch.await(30, TimeUnit.SECONDS);
+            if (latch.await(30L, TimeUnit.SECONDS) == false) {
+                fail("Failed to get all expected responses.");
+            }
 
         } finally {
             if (channelFuture != null) {

plugins/examples/custom-suggester/build.gradle

@@ -0,0 +1,33 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+apply plugin: 'elasticsearch.esplugin'
+
+esplugin {
+    name 'custom-suggester'
+    description 'An example plugin showing how to write and register a custom suggester'
+    classname 'org.elasticsearch.example.customsuggester.CustomSuggesterPlugin'
+}
+
+integTestCluster {
+    numNodes = 2
+}
+
+// this plugin has no unit tests, only rest tests
+tasks.test.enabled = false

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggester.java

@@ -0,0 +1,62 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.example.customsuggester;
+
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.util.CharsRefBuilder;
+import org.elasticsearch.common.text.Text;
+import org.elasticsearch.search.suggest.Suggest;
+import org.elasticsearch.search.suggest.Suggester;
+
+import java.util.Locale;
+
+public class CustomSuggester extends Suggester<CustomSuggestionContext> {
+
+    // This is a pretty dumb implementation which returns the original text + fieldName + custom config option + 12 or 123
+    @Override
+    public Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>> innerExecute(
+        String name,
+        CustomSuggestionContext suggestion,
+        IndexSearcher searcher,
+        CharsRefBuilder spare) {
+
+        // Get the suggestion context
+        String text = suggestion.getText().utf8ToString();
+
+        // create two suggestions with 12 and 123 appended
+        CustomSuggestion response = new CustomSuggestion(name, suggestion.getSize(), "suggestion-dummy-value");
+
+        CustomSuggestion.Entry entry = new CustomSuggestion.Entry(new Text(text), 0, text.length(), "entry-dummy-value");
+
+        String firstOption =
+            String.format(Locale.ROOT, "%s-%s-%s-%s", text, suggestion.getField(), suggestion.options.get("suffix"), "12");
+        CustomSuggestion.Entry.Option option12 = new CustomSuggestion.Entry.Option(new Text(firstOption), 0.9f, "option-dummy-value-1");
+        entry.addOption(option12);
+
+        String secondOption =
+            String.format(Locale.ROOT, "%s-%s-%s-%s", text, suggestion.getField(), suggestion.options.get("suffix"), "123");
+        CustomSuggestion.Entry.Option option123 = new CustomSuggestion.Entry.Option(new Text(secondOption), 0.8f, "option-dummy-value-2");
+        entry.addOption(option123);
+
+        response.addTerm(entry);
+
+        return response;
+    }
+}

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggesterPlugin.java

@@ -0,0 +1,40 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.example.customsuggester;
+
+import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.plugins.SearchPlugin;
+
+import java.util.Collections;
+import java.util.List;
+
+public class CustomSuggesterPlugin extends Plugin implements SearchPlugin {
+    @Override
+    public List<SearchPlugin.SuggesterSpec<?>> getSuggesters() {
+        return Collections.singletonList(
+            new SearchPlugin.SuggesterSpec<>(
+                CustomSuggestionBuilder.SUGGESTION_NAME,
+                CustomSuggestionBuilder::new,
+                CustomSuggestionBuilder::fromXContent,
+                CustomSuggestion::new
+            )
+        );
+    }
+}

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggestion.java

@@ -0,0 +1,227 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.example.customsuggester;
+
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.text.Text;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.ObjectParser;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.search.suggest.Suggest;
+
+import java.io.IOException;
+
+import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
+
+public class CustomSuggestion extends Suggest.Suggestion<CustomSuggestion.Entry> {
+
+    public static final int TYPE = 999;
+
+    public static final ParseField DUMMY = new ParseField("dummy");
+
+    private String dummy;
+
+    public CustomSuggestion(String name, int size, String dummy) {
+        super(name, size);
+        this.dummy = dummy;
+    }
+
+    public CustomSuggestion(StreamInput in) throws IOException {
+        super(in);
+        dummy = in.readString();
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+        out.writeString(dummy);
+    }
+
+    @Override
+    public String getWriteableName() {
+        return CustomSuggestionBuilder.SUGGESTION_NAME;
+    }
+
+    @Override
+    public int getWriteableType() {
+        return TYPE;
+    }
+
+    /**
+     * A meaningless value used to test that plugin suggesters can add fields to their Suggestion types
+     *
+     * This can't be serialized to xcontent because Suggestions appear in xcontent as an array of entries, so there is no place
+     * to add a custom field. But we can still use a custom field internally and use it to define a Suggestion's behavior
+     */
+    public String getDummy() {
+        return dummy;
+    }
+
+    @Override
+    protected Entry newEntry() {
+        return new Entry();
+    }
+
+    @Override
+    protected Entry newEntry(StreamInput in) throws IOException {
+        return new Entry(in);
+    }
+
+    public static CustomSuggestion fromXContent(XContentParser parser, String name) throws IOException {
+        CustomSuggestion suggestion = new CustomSuggestion(name, -1, null);
+        parseEntries(parser, suggestion, Entry::fromXContent);
+        return suggestion;
+    }
+
+    public static class Entry extends Suggest.Suggestion.Entry<CustomSuggestion.Entry.Option> {
+
+        private static final ObjectParser<Entry, Void> PARSER = new ObjectParser<>("CustomSuggestionEntryParser", true, Entry::new);
+
+        static {
+            declareCommonFields(PARSER);
+            PARSER.declareString((entry, dummy) -> entry.dummy = dummy, DUMMY);
+            PARSER.declareObjectArray(Entry::addOptions, (p, c) -> Option.fromXContent(p), new ParseField(OPTIONS));
+        }
+
+        private String dummy;
+
+        public Entry() {}
+
+        public Entry(Text text, int offset, int length, String dummy) {
+            super(text, offset, length);
+            this.dummy = dummy;
+        }
+
+        public Entry(StreamInput in) throws IOException {
+            super(in);
+            dummy = in.readString();
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            super.writeTo(out);
+            out.writeString(dummy);
+        }
+
+        @Override
+        protected Option newOption() {
+            return new Option();
+        }
+
+        @Override
+        protected Option newOption(StreamInput in) throws IOException {
+            return new Option(in);
+        }
+
+        /*
+         * the value of dummy will always be the same, so this just tests that we can merge entries with custom fields
+         */
+        @Override
+        protected void merge(Suggest.Suggestion.Entry<Option> otherEntry) {
+            dummy = ((Entry) otherEntry).getDummy();
+        }
+
+        /**
+         * Meaningless field used to test that plugin suggesters can add fields to their entries
+         */
+        public String getDummy() {
+            return dummy;
+        }
+
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            builder = super.toXContent(builder, params);
+            builder.field(DUMMY.getPreferredName(), getDummy());
+            return builder;
+        }
+
+        public static Entry fromXContent(XContentParser parser) {
+            return PARSER.apply(parser, null);
+        }
+
+        public static class Option extends Suggest.Suggestion.Entry.Option {
+
+            private static final ConstructingObjectParser<Option, Void> PARSER = new ConstructingObjectParser<>(
+                "CustomSuggestionObjectParser", true,
+                args -> {
+                    Text text = new Text((String) args[0]);
+                    float score = (float) args[1];
+                    String dummy = (String) args[2];
+                    return new Option(text, score, dummy);
+                });
+
+            static {
+                PARSER.declareString(constructorArg(), TEXT);
+                PARSER.declareFloat(constructorArg(), SCORE);
+                PARSER.declareString(constructorArg(), DUMMY);
+            }
+
+            private String dummy;
+
+            public Option() {}
+
+            public Option(Text text, float score, String dummy) {
+                super(text, score);
+                this.dummy = dummy;
+            }
+
+            public Option(StreamInput in) throws IOException {
+                super(in);
+                dummy = in.readString();
+            }
+
+            @Override
+            public void writeTo(StreamOutput out) throws IOException {
+                super.writeTo(out);
+                out.writeString(dummy);
+            }
+
+            /**
+             * A meaningless value used to test that plugin suggesters can add fields to their options
+             */
+            public String getDummy() {
+                return dummy;
+            }
+
+            /*
+             * the value of dummy will always be the same, so this just tests that we can merge options with custom fields
+             */
+            @Override
+            protected void mergeInto(Suggest.Suggestion.Entry.Option otherOption) {
+                super.mergeInto(otherOption);
+                dummy = ((Option) otherOption).getDummy();
+            }
+
+            @Override
+            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+                builder = super.toXContent(builder, params);
+                builder.field(DUMMY.getPreferredName(), dummy);
+                return builder;
+            }
+
+            public static Option fromXContent(XContentParser parser) {
+                return PARSER.apply(parser, null);
+            }
+        }
+    }
+}

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggestionBuilder.java

@@ -0,0 +1,143 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.example.customsuggester;
+
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParsingException;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.lucene.BytesRefs;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.index.query.QueryShardContext;
+import org.elasticsearch.search.suggest.SuggestionBuilder;
+import org.elasticsearch.search.suggest.SuggestionSearchContext;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+public class CustomSuggestionBuilder extends SuggestionBuilder<CustomSuggestionBuilder> {
+
+    public static final String SUGGESTION_NAME = "custom";
+
+    protected static final ParseField RANDOM_SUFFIX_FIELD = new ParseField("suffix");
+
+    private String randomSuffix;
+
+    public CustomSuggestionBuilder(String randomField, String randomSuffix) {
+        super(randomField);
+        this.randomSuffix = randomSuffix;
+    }
+
+    /**
+     * Read from a stream.
+     */
+    public CustomSuggestionBuilder(StreamInput in) throws IOException {
+        super(in);
+        this.randomSuffix = in.readString();
+    }
+
+    @Override
+    public void doWriteTo(StreamOutput out) throws IOException {
+        out.writeString(randomSuffix);
+    }
+
+    @Override
+    protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.field(RANDOM_SUFFIX_FIELD.getPreferredName(), randomSuffix);
+        return builder;
+    }
+
+    @Override
+    public String getWriteableName() {
+        return SUGGESTION_NAME;
+    }
+
+    @Override
+    protected boolean doEquals(CustomSuggestionBuilder other) {
+        return Objects.equals(randomSuffix, other.randomSuffix);
+    }
+
+    @Override
+    protected int doHashCode() {
+        return Objects.hash(randomSuffix);
+    }
+
+    public static CustomSuggestionBuilder fromXContent(XContentParser parser) throws IOException {
+        XContentParser.Token token;
+        String currentFieldName = null;
+        String fieldname = null;
+        String suffix = null;
+        String analyzer = null;
+        int sizeField = -1;
+        int shardSize = -1;
+        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+            if (token == XContentParser.Token.FIELD_NAME) {
+                currentFieldName = parser.currentName();
+            } else if (token.isValue()) {
+                if (SuggestionBuilder.ANALYZER_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    analyzer = parser.text();
+                } else if (SuggestionBuilder.FIELDNAME_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    fieldname = parser.text();
+                } else if (SuggestionBuilder.SIZE_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    sizeField = parser.intValue();
+                } else if (SuggestionBuilder.SHARDSIZE_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    shardSize = parser.intValue();
+                } else if (RANDOM_SUFFIX_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    suffix = parser.text();
+                }
+            } else {
+                throw new ParsingException(parser.getTokenLocation(),
+                    "suggester[custom] doesn't support field [" + currentFieldName + "]");
+            }
+        }
+
+        // now we should have field name, check and copy fields over to the suggestion builder we return
+        if (fieldname == null) {
+            throw new ParsingException(parser.getTokenLocation(), "the required field option is missing");
+        }
+        CustomSuggestionBuilder builder = new CustomSuggestionBuilder(fieldname, suffix);
+        if (analyzer != null) {
+            builder.analyzer(analyzer);
+        }
+        if (sizeField != -1) {
+            builder.size(sizeField);
+        }
+        if (shardSize != -1) {
+            builder.shardSize(shardSize);
+        }
+        return builder;
+    }
+
+    @Override
+    public SuggestionSearchContext.SuggestionContext build(QueryShardContext context) throws IOException {
+        Map<String, Object> options = new HashMap<>();
+        options.put(FIELDNAME_FIELD.getPreferredName(), field());
+        options.put(RANDOM_SUFFIX_FIELD.getPreferredName(), randomSuffix);
+        CustomSuggestionContext customSuggestionsContext = new CustomSuggestionContext(context, options);
+        customSuggestionsContext.setField(field());
+        assert text != null;
+        customSuggestionsContext.setText(BytesRefs.toBytesRef(text));
+        return customSuggestionsContext;
+    }
+
+}

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggestionContext.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.example.customsuggester;
+
+import org.elasticsearch.index.query.QueryShardContext;
+import org.elasticsearch.search.suggest.SuggestionSearchContext;
+
+import java.util.Map;
+
+public class CustomSuggestionContext extends SuggestionSearchContext.SuggestionContext {
+
+    public Map<String, Object> options;
+
+    public CustomSuggestionContext(QueryShardContext context, Map<String, Object> options) {
+        super(new CustomSuggester(), context);
+        this.options = options;
+    }
+}

plugins/examples/custom-suggester/src/test/java/org/elasticsearch/example/customsuggester/CustomSuggesterClientYamlTestSuiteIT.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.example.customsuggester;
+
+import com.carrotsearch.randomizedtesting.annotations.Name;
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+import org.elasticsearch.test.rest.yaml.ClientYamlTestCandidate;
+import org.elasticsearch.test.rest.yaml.ESClientYamlSuiteTestCase;
+
+public class CustomSuggesterClientYamlTestSuiteIT extends ESClientYamlSuiteTestCase {
+
+    public CustomSuggesterClientYamlTestSuiteIT(@Name("yaml") ClientYamlTestCandidate testCandidate) {
+        super(testCandidate);
+    }
+
+    @ParametersFactory
+    public static Iterable<Object[]> parameters() throws Exception {
+        return ESClientYamlSuiteTestCase.createParameters();
+    }
+}

plugins/examples/custom-suggester/src/test/resources/rest-api-spec/test/custom-suggester/10_basic.yml

@@ -0,0 +1,13 @@
+# tests that the custom suggester plugin is installed
+---
+"plugin loaded":
+    - do:
+        cluster.state: {}
+
+    # Get master node id
+    - set: { master_node: master }
+
+    - do:
+        nodes.info: {}
+
+    - contains:  { nodes.$master.plugins: { name: custom-suggester } }

plugins/examples/custom-suggester/src/test/resources/rest-api-spec/test/custom-suggester/20_suggest.yml

@@ -0,0 +1,55 @@
+# tests that the custom suggester works
+
+# the issue that prompted serializing Suggestion as a registered named writeable was not revealed until
+# a user found that it would fail when reducing suggestions in a multi node envrionment
+# https://github.com/elastic/elasticsearch/issues/26585
+"test custom suggester":
+  - do:
+      cluster.health:
+        wait_for_nodes: 2
+
+  - is_true: cluster_name
+  - is_false: timed_out
+  - gte: { number_of_nodes: 2 }
+  - gte: { number_of_data_nodes: 2 }
+
+  - do:
+      indices.create:
+        index: test
+        body:
+          settings:
+            number_of_shards: 2
+            number_of_replicas: 0
+
+  - do:
+      bulk:
+        index: test
+        type: test
+        refresh: true
+        body: |
+          { "index": {} }
+          { "content": "these" }
+          { "index": {} }
+          { "content": "aren't" }
+          { "index": {} }
+          { "content": "actually" }
+          { "index": {} }
+          { "content": "used" }
+
+  - do:
+      search:
+        size: 0
+        index: test
+        body:
+          suggest:
+            test:
+              text: my suggestion text
+              custom:
+                field: arbitraryField
+                suffix: arbitrarySuffix
+
+  - match: { suggest.test.0.dummy: entry-dummy-value }
+  - match: { suggest.test.0.options.0.text: my suggestion text-arbitraryField-arbitrarySuffix-12 }
+  - match: { suggest.test.0.options.0.dummy: option-dummy-value-1 }
+  - match: { suggest.test.0.options.1.text: my suggestion text-arbitraryField-arbitrarySuffix-123 }
+  - match: { suggest.test.0.options.1.dummy: option-dummy-value-2 }

plugins/ingest-geoip/licenses/jackson-annotations-2.8.10.jar.sha1

@@ -1 +0,0 @@
-5e924646d6f893bc9036939c5f2b4ecaee85e5da

plugins/ingest-geoip/licenses/jackson-annotations-2.8.11.jar.sha1

@@ -0,0 +1 @@
+391de20b4e29cb3fb07d2454ace64be2c82ac91f

plugins/ingest-geoip/licenses/jackson-databind-2.8.10.jar.sha1

@@ -1 +0,0 @@
-f7b83cb2bc4b88d53961e749e1ad32f49ef017b7

plugins/ingest-geoip/licenses/jackson-databind-2.8.11.jar.sha1

@@ -0,0 +1 @@
+0569a9f220273024523799dba9dd358121b0ee09

plugins/transport-nio/src/test/java/org/elasticsearch/http/nio/Netty4HttpClient.java

@@ -1,201 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.http.nio;
-
-import io.netty.bootstrap.Bootstrap;
-import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
-import io.netty.channel.ChannelFuture;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInitializer;
-import io.netty.channel.SimpleChannelInboundHandler;
-import io.netty.channel.nio.NioEventLoopGroup;
-import io.netty.channel.socket.SocketChannel;
-import io.netty.channel.socket.nio.NioSocketChannel;
-import io.netty.handler.codec.http.DefaultFullHttpRequest;
-import io.netty.handler.codec.http.FullHttpRequest;
-import io.netty.handler.codec.http.FullHttpResponse;
-import io.netty.handler.codec.http.HttpHeaderNames;
-import io.netty.handler.codec.http.HttpMethod;
-import io.netty.handler.codec.http.HttpObject;
-import io.netty.handler.codec.http.HttpObjectAggregator;
-import io.netty.handler.codec.http.HttpRequest;
-import io.netty.handler.codec.http.HttpRequestEncoder;
-import io.netty.handler.codec.http.HttpResponse;
-import io.netty.handler.codec.http.HttpResponseDecoder;
-import io.netty.handler.codec.http.HttpVersion;
-import org.elasticsearch.common.collect.Tuple;
-import org.elasticsearch.common.unit.ByteSizeUnit;
-import org.elasticsearch.common.unit.ByteSizeValue;
-import org.elasticsearch.tasks.Task;
-
-import java.io.Closeable;
-import java.net.SocketAddress;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-
-import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
-import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
-
-/**
- * Tiny helper to send http requests over netty.
- */
-class Netty4HttpClient implements Closeable {
-
-    static Collection<String> returnHttpResponseBodies(Collection<FullHttpResponse> responses) {
-        List<String> list = new ArrayList<>(responses.size());
-        for (FullHttpResponse response : responses) {
-            list.add(response.content().toString(StandardCharsets.UTF_8));
-        }
-        return list;
-    }
-
-    static Collection<String> returnOpaqueIds(Collection<FullHttpResponse> responses) {
-        List<String> list = new ArrayList<>(responses.size());
-        for (HttpResponse response : responses) {
-            list.add(response.headers().get(Task.X_OPAQUE_ID));
-        }
-        return list;
-    }
-
-    private final Bootstrap clientBootstrap;
-
-    Netty4HttpClient() {
-        clientBootstrap = new Bootstrap().channel(NioSocketChannel.class).group(new NioEventLoopGroup());
-    }
-
-    public Collection<FullHttpResponse> get(SocketAddress remoteAddress, String... uris) throws InterruptedException {
-        Collection<HttpRequest> requests = new ArrayList<>(uris.length);
-        for (int i = 0; i < uris.length; i++) {
-            final HttpRequest httpRequest = new DefaultFullHttpRequest(HTTP_1_1, HttpMethod.GET, uris[i]);
-            httpRequest.headers().add(HOST, "localhost");
-            httpRequest.headers().add(Task.X_OPAQUE_ID, String.valueOf(i));
-            requests.add(httpRequest);
-        }
-        return sendRequests(remoteAddress, requests);
-    }
-
-    @SafeVarargs // Safe not because it doesn't do anything with the type parameters but because it won't leak them into other methods.
-    public final Collection<FullHttpResponse> post(SocketAddress remoteAddress, Tuple<String, CharSequence>... urisAndBodies)
-        throws InterruptedException {
-        return processRequestsWithBody(HttpMethod.POST, remoteAddress, urisAndBodies);
-    }
-
-    public final FullHttpResponse post(SocketAddress remoteAddress, FullHttpRequest httpRequest) throws InterruptedException {
-        Collection<FullHttpResponse> responses = sendRequests(remoteAddress, Collections.singleton(httpRequest));
-        assert responses.size() == 1 : "expected 1 and only 1 http response";
-        return responses.iterator().next();
-    }
-
-    @SafeVarargs // Safe not because it doesn't do anything with the type parameters but because it won't leak them into other methods.
-    public final Collection<FullHttpResponse> put(SocketAddress remoteAddress, Tuple<String, CharSequence>... urisAndBodies)
-        throws InterruptedException {
-        return processRequestsWithBody(HttpMethod.PUT, remoteAddress, urisAndBodies);
-    }
-
-    private Collection<FullHttpResponse> processRequestsWithBody(HttpMethod method, SocketAddress remoteAddress, Tuple<String,
-        CharSequence>... urisAndBodies) throws InterruptedException {
-        Collection<HttpRequest> requests = new ArrayList<>(urisAndBodies.length);
-        for (Tuple<String, CharSequence> uriAndBody : urisAndBodies) {
-            ByteBuf content = Unpooled.copiedBuffer(uriAndBody.v2(), StandardCharsets.UTF_8);
-            HttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, method, uriAndBody.v1(), content);
-            request.headers().add(HttpHeaderNames.HOST, "localhost");
-            request.headers().add(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());
-            request.headers().add(HttpHeaderNames.CONTENT_TYPE, "application/json");
-            requests.add(request);
-        }
-        return sendRequests(remoteAddress, requests);
-    }
-
-    private synchronized Collection<FullHttpResponse> sendRequests(
-        final SocketAddress remoteAddress,
-        final Collection<HttpRequest> requests) throws InterruptedException {
-        final CountDownLatch latch = new CountDownLatch(requests.size());
-        final Collection<FullHttpResponse> content = Collections.synchronizedList(new ArrayList<>(requests.size()));
-
-        clientBootstrap.handler(new CountDownLatchHandler(latch, content));
-
-        ChannelFuture channelFuture = null;
-        try {
-            channelFuture = clientBootstrap.connect(remoteAddress);
-            channelFuture.sync();
-
-            for (HttpRequest request : requests) {
-                channelFuture.channel().writeAndFlush(request);
-            }
-            latch.await(30, TimeUnit.SECONDS);
-
-        } finally {
-            if (channelFuture != null) {
-                channelFuture.channel().close().sync();
-            }
-        }
-
-        return content;
-    }
-
-    @Override
-    public void close() {
-        clientBootstrap.config().group().shutdownGracefully().awaitUninterruptibly();
-    }
-
-    /**
-     * helper factory which adds returned data to a list and uses a count down latch to decide when done
-     */
-    private static class CountDownLatchHandler extends ChannelInitializer<SocketChannel> {
-
-        private final CountDownLatch latch;
-        private final Collection<FullHttpResponse> content;
-
-        CountDownLatchHandler(final CountDownLatch latch, final Collection<FullHttpResponse> content) {
-            this.latch = latch;
-            this.content = content;
-        }
-
-        @Override
-        protected void initChannel(SocketChannel ch) throws Exception {
-            final int maxContentLength = new ByteSizeValue(100, ByteSizeUnit.MB).bytesAsInt();
-            ch.pipeline().addLast(new HttpResponseDecoder());
-            ch.pipeline().addLast(new HttpRequestEncoder());
-            ch.pipeline().addLast(new HttpObjectAggregator(maxContentLength));
-            ch.pipeline().addLast(new SimpleChannelInboundHandler<HttpObject>() {
-                @Override
-                protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
-                    final FullHttpResponse response = (FullHttpResponse) msg;
-                    content.add(response.copy());
-                    latch.countDown();
-                }
-
-                @Override
-                public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-                    super.exceptionCaught(ctx, cause);
-                    latch.countDown();
-                }
-            });
-        }
-
-    }
-
-}

plugins/transport-nio/src/test/java/org/elasticsearch/http/nio/NioHttpClient.java

@@ -0,0 +1,285 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.http.nio;
+
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelHandler;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpObjectAggregator;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpRequestEncoder;
+import io.netty.handler.codec.http.HttpResponse;
+import io.netty.handler.codec.http.HttpResponseDecoder;
+import org.apache.logging.log4j.Logger;
+import org.elasticsearch.action.ActionListener;
+import org.elasticsearch.action.support.PlainActionFuture;
+import org.elasticsearch.common.logging.Loggers;
+import org.elasticsearch.common.network.NetworkService;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.unit.ByteSizeUnit;
+import org.elasticsearch.common.unit.ByteSizeValue;
+import org.elasticsearch.core.internal.io.IOUtils;
+import org.elasticsearch.nio.BytesChannelContext;
+import org.elasticsearch.nio.ChannelFactory;
+import org.elasticsearch.nio.EventHandler;
+import org.elasticsearch.nio.FlushOperation;
+import org.elasticsearch.nio.InboundChannelBuffer;
+import org.elasticsearch.nio.NioGroup;
+import org.elasticsearch.nio.NioSelector;
+import org.elasticsearch.nio.NioServerSocketChannel;
+import org.elasticsearch.nio.NioSocketChannel;
+import org.elasticsearch.nio.ReadWriteHandler;
+import org.elasticsearch.nio.SocketChannelContext;
+import org.elasticsearch.nio.WriteOperation;
+import org.elasticsearch.tasks.Task;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.net.InetSocketAddress;
+import java.nio.channels.ServerSocketChannel;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+import static io.netty.handler.codec.http.HttpHeaderNames.HOST;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+import static org.elasticsearch.common.util.concurrent.EsExecutors.daemonThreadFactory;
+import static org.junit.Assert.fail;
+
+/**
+ * Tiny helper to send http requests over nio.
+ */
+class NioHttpClient implements Closeable {
+
+    static Collection<String> returnOpaqueIds(Collection<FullHttpResponse> responses) {
+        List<String> list = new ArrayList<>(responses.size());
+        for (HttpResponse response : responses) {
+            list.add(response.headers().get(Task.X_OPAQUE_ID));
+        }
+        return list;
+    }
+
+    private final NioGroup nioGroup;
+    private final Logger logger;
+
+    NioHttpClient() {
+        logger = Loggers.getLogger(NioHttpClient.class, Settings.EMPTY);
+        try {
+            nioGroup = new NioGroup(daemonThreadFactory(Settings.EMPTY, "nio-http-client"), 1,
+                (s) -> new EventHandler(this::onException, s));
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    public Collection<FullHttpResponse> get(InetSocketAddress remoteAddress, String... uris) throws InterruptedException {
+        Collection<HttpRequest> requests = new ArrayList<>(uris.length);
+        for (int i = 0; i < uris.length; i++) {
+            final HttpRequest httpRequest = new DefaultFullHttpRequest(HTTP_1_1, HttpMethod.GET, uris[i]);
+            httpRequest.headers().add(HOST, "localhost");
+            httpRequest.headers().add(Task.X_OPAQUE_ID, String.valueOf(i));
+            requests.add(httpRequest);
+        }
+        return sendRequests(remoteAddress, requests);
+    }
+
+    public final FullHttpResponse post(InetSocketAddress remoteAddress, FullHttpRequest httpRequest) throws InterruptedException {
+        Collection<FullHttpResponse> responses = sendRequests(remoteAddress, Collections.singleton(httpRequest));
+        assert responses.size() == 1 : "expected 1 and only 1 http response";
+        return responses.iterator().next();
+    }
+
+    private void onException(Exception e) {
+        logger.error("Exception from http client", e);
+    }
+
+    private synchronized Collection<FullHttpResponse> sendRequests(InetSocketAddress remoteAddress, Collection<HttpRequest> requests)
+        throws InterruptedException {
+        final CountDownLatch latch = new CountDownLatch(requests.size());
+        final Collection<FullHttpResponse> content = Collections.synchronizedList(new ArrayList<>(requests.size()));
+
+        ChannelFactory<NioServerSocketChannel, NioSocketChannel> factory = new ClientChannelFactory(latch, content);
+
+        NioSocketChannel nioSocketChannel = null;
+        try {
+            nioSocketChannel = nioGroup.openChannel(remoteAddress, factory);
+            PlainActionFuture<Void> connectFuture = PlainActionFuture.newFuture();
+            nioSocketChannel.addConnectListener(ActionListener.toBiConsumer(connectFuture));
+            connectFuture.actionGet();
+
+            for (HttpRequest request : requests) {
+                nioSocketChannel.getContext().sendMessage(request, (v, e) -> {});
+            }
+            if (latch.await(30L, TimeUnit.SECONDS) == false) {
+                fail("Failed to get all expected responses.");
+            }
+
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        } finally {
+            if (nioSocketChannel != null) {
+                nioSocketChannel.close();
+            }
+        }
+
+        return content;
+    }
+
+    @Override
+    public void close() {
+        IOUtils.closeWhileHandlingException(nioGroup::close);
+    }
+
+    private class ClientChannelFactory extends ChannelFactory<NioServerSocketChannel, NioSocketChannel> {
+
+        private final CountDownLatch latch;
+        private final Collection<FullHttpResponse> content;
+
+        private ClientChannelFactory(CountDownLatch latch, Collection<FullHttpResponse> content) {
+            super(new RawChannelFactory(NetworkService.TCP_NO_DELAY.get(Settings.EMPTY),
+                NetworkService.TCP_KEEP_ALIVE.get(Settings.EMPTY),
+                NetworkService.TCP_REUSE_ADDRESS.get(Settings.EMPTY),
+                Math.toIntExact(NetworkService.TCP_SEND_BUFFER_SIZE.get(Settings.EMPTY).getBytes()),
+                Math.toIntExact(NetworkService.TCP_RECEIVE_BUFFER_SIZE.get(Settings.EMPTY).getBytes())));
+            this.latch = latch;
+            this.content = content;
+        }
+
+        @Override
+        public NioSocketChannel createChannel(NioSelector selector, java.nio.channels.SocketChannel channel) throws IOException {
+            NioSocketChannel nioSocketChannel = new NioSocketChannel(channel);
+            HttpClientHandler handler = new HttpClientHandler(nioSocketChannel, latch, content);
+            Consumer<Exception> exceptionHandler = (e) -> {
+                latch.countDown();
+                onException(e);
+                nioSocketChannel.close();
+            };
+            SocketChannelContext context = new BytesChannelContext(nioSocketChannel, selector, exceptionHandler, handler,
+                InboundChannelBuffer.allocatingInstance());
+            nioSocketChannel.setContext(context);
+            return nioSocketChannel;
+        }
+
+        @Override
+        public NioServerSocketChannel createServerChannel(NioSelector selector, ServerSocketChannel channel) {
+            throw new UnsupportedOperationException("Cannot create server channel");
+        }
+    }
+
+    private static class HttpClientHandler implements ReadWriteHandler {
+
+        private final NettyAdaptor adaptor;
+        private final CountDownLatch latch;
+        private final Collection<FullHttpResponse> content;
+
+        private HttpClientHandler(NioSocketChannel channel, CountDownLatch latch, Collection<FullHttpResponse> content) {
+            this.latch = latch;
+            this.content = content;
+            final int maxContentLength = Math.toIntExact(new ByteSizeValue(100, ByteSizeUnit.MB).getBytes());
+            List<ChannelHandler> handlers = new ArrayList<>(5);
+            handlers.add(new HttpResponseDecoder());
+            handlers.add(new HttpRequestEncoder());
+            handlers.add(new HttpObjectAggregator(maxContentLength));
+
+            adaptor = new NettyAdaptor(handlers.toArray(new ChannelHandler[0]));
+            adaptor.addCloseListener((v, e) -> channel.close());
+        }
+
+        @Override
+        public WriteOperation createWriteOperation(SocketChannelContext context, Object message, BiConsumer<Void, Exception> listener) {
+            assert message instanceof HttpRequest : "Expected type HttpRequest.class, found: " + message.getClass();
+            return new WriteOperation() {
+                @Override
+                public BiConsumer<Void, Exception> getListener() {
+                    return listener;
+                }
+
+                @Override
+                public SocketChannelContext getChannel() {
+                    return context;
+                }
+
+                @Override
+                public Object getObject() {
+                    return message;
+                }
+            };
+        }
+
+        @Override
+        public List<FlushOperation> writeToBytes(WriteOperation writeOperation) {
+            adaptor.write(writeOperation);
+            return pollFlushOperations();
+        }
+
+        @Override
+        public List<FlushOperation> pollFlushOperations() {
+            ArrayList<FlushOperation> copiedOperations = new ArrayList<>(adaptor.getOutboundCount());
+            FlushOperation flushOperation;
+            while ((flushOperation = adaptor.pollOutboundOperation()) != null) {
+                copiedOperations.add(flushOperation);
+            }
+            return copiedOperations;
+        }
+
+        @Override
+        public int consumeReads(InboundChannelBuffer channelBuffer) throws IOException {
+            int bytesConsumed = adaptor.read(channelBuffer.sliceAndRetainPagesTo(channelBuffer.getIndex()));
+            Object message;
+            while ((message = adaptor.pollInboundMessage()) != null) {
+                handleRequest(message);
+            }
+
+            return bytesConsumed;
+        }
+
+        @Override
+        public void close() throws IOException {
+            try {
+                adaptor.close();
+            } catch (Exception e) {
+                throw new IOException(e);
+            }
+        }
+
+        private void handleRequest(Object message) {
+            final FullHttpResponse response = (FullHttpResponse) message;
+            DefaultFullHttpResponse newResponse = new DefaultFullHttpResponse(response.protocolVersion(),
+                response.status(),
+                Unpooled.copiedBuffer(response.content()),
+                response.headers().copy(),
+                response.trailingHeaders().copy());
+            response.release();
+            content.add(newResponse);
+            latch.countDown();
+        }
+    }
+
+}

plugins/transport-nio/src/test/java/org/elasticsearch/http/nio/NioHttpServerTransportTests.java

@@ -192,7 +192,7 @@ public class NioHttpServerTransportTests extends ESTestCase {
             xContentRegistry(), dispatcher)) {
             transport.start();
             final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
-            try (Netty4HttpClient client = new Netty4HttpClient()) {
+            try (NioHttpClient client = new NioHttpClient()) {
                 final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.POST, "/");
                 request.headers().set(HttpHeaderNames.EXPECT, expectation);
                 HttpUtil.setContentLength(request, contentLength);
@@ -275,7 +275,7 @@ public class NioHttpServerTransportTests extends ESTestCase {
             transport.start();
             final TransportAddress remoteAddress = randomFrom(transport.boundAddress().boundAddresses());
 
-            try (Netty4HttpClient client = new Netty4HttpClient()) {
+            try (NioHttpClient client = new NioHttpClient()) {
                 final String url = "/" + new String(new byte[maxInitialLineLength], Charset.forName("UTF-8"));
                 final FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, url);
 

plugins/transport-nio/src/test/java/org/elasticsearch/http/nio/NioPipeliningIT.java

@@ -47,11 +47,11 @@ public class NioPipeliningIT extends NioIntegTestCase {
         TransportAddress[] boundAddresses = httpServerTransport.boundAddress().boundAddresses();
         TransportAddress transportAddress = randomFrom(boundAddresses);
 
-        try (Netty4HttpClient nettyHttpClient = new Netty4HttpClient()) {
+        try (NioHttpClient nettyHttpClient = new NioHttpClient()) {
             Collection<FullHttpResponse> responses = nettyHttpClient.get(transportAddress.address(), requests);
             assertThat(responses, hasSize(5));
 
-            Collection<String> opaqueIds = Netty4HttpClient.returnOpaqueIds(responses);
+            Collection<String> opaqueIds = NioHttpClient.returnOpaqueIds(responses);
             assertOpaqueIdsInOrder(opaqueIds);
         }
     }

qa/vagrant/src/test/resources/packaging/tests/60_systemd.bats

@@ -189,7 +189,10 @@ setup() {
 
 @test "[SYSTEMD] start Elasticsearch with custom JVM options" {
     assert_file_exist $ESENVFILE
-    local temp=`mktemp -d`
+    # The custom config directory is not under /tmp or /var/tmp because
+    # systemd's private temp directory functionaly means different
+    # processes can have different views of what's in these directories
+    local temp=`mktemp -p /etc -d`
     cp "$ESCONFIG"/elasticsearch.yml "$temp"
     cp "$ESCONFIG"/log4j2.properties "$temp"
     touch "$temp/jvm.options"

qa/vagrant/src/test/resources/packaging/tests/module_and_plugin_test_cases.bash

@@ -92,11 +92,14 @@ fi
 
 @test "[$GROUP] install a sample plugin with a symlinked plugins path" {
     # Clean up after the last time this test was run
-    rm -rf /tmp/plugins.*
-    rm -rf /tmp/old_plugins.*
+    rm -rf /var/plugins.*
+    rm -rf /var/old_plugins.*
 
     rm -rf "$ESPLUGINS"
-    local es_plugins=$(mktemp -d -t 'plugins.XXXX')
+    # The custom plugins directory is not under /tmp or /var/tmp because
+    # systemd's private temp directory functionaly means different
+    # processes can have different views of what's in these directories
+    local es_plugins=$(mktemp -p /var -d -t 'plugins.XXXX')
     chown -R elasticsearch:elasticsearch "$es_plugins"
     ln -s "$es_plugins" "$ESPLUGINS"
 

qa/vagrant/src/test/resources/packaging/utils/utils.bash

@@ -555,7 +555,10 @@ run_elasticsearch_tests() {
 # Move the config directory to another directory and properly chown it.
 move_config() {
     local oldConfig="$ESCONFIG"
-    export ESCONFIG="${1:-$(mktemp -d -t 'config.XXXX')}"
+    # The custom config directory is not under /tmp or /var/tmp because
+    # systemd's private temp directory functionaly means different
+    # processes can have different views of what's in these directories
+    export ESCONFIG="${1:-$(mktemp -p /etc -d -t 'config.XXXX')}"
     echo "Moving configuration directory from $oldConfig to $ESCONFIG"
 
     # Move configuration files to the new configuration directory

rest-api-spec/src/main/resources/rest-api-spec/test/search/110_field_collapsing.yml

@@ -1,7 +1,14 @@
 setup:
   - do:
       indices.create:
-          index:  test
+        index:  test
+        body:
+          mappings:
+            test:
+              properties:
+                numeric_group: { type: integer }
+                group_alias: { type: alias, path: numeric_group }
+
   - do:
       index:
           index:  test
@@ -341,3 +348,25 @@ setup:
   - match: { hits.hits.2.inner_hits.sub_hits.hits.hits.0._version: 55 }
   - match: { hits.hits.2.inner_hits.sub_hits.hits.hits.1._id: "4" }
   - match: { hits.hits.2.inner_hits.sub_hits.hits.hits.1._version: 44 }
+
+---
+"field collapsing on a field alias":
+  - skip:
+      version: " - 6.3.99"
+      reason: Field aliases were introduced in 6.4.0.
+  - do:
+      search:
+        index: test
+        body:
+          collapse: { field: group_alias, inner_hits: { name: sub_hits } }
+          sort: [{ sort: desc }]
+
+  - match: { hits.total: 6 }
+  - length: { hits.hits: 3 }
+
+  - match: { hits.hits.0.fields.group_alias: [3] }
+  - match: { hits.hits.0.inner_hits.sub_hits.hits.total: 1}
+  - match: { hits.hits.1.fields.group_alias: [1] }
+  - match: { hits.hits.1.inner_hits.sub_hits.hits.total: 3}
+  - match: { hits.hits.2.fields.group_alias: [25] }
+  - match: { hits.hits.2.inner_hits.sub_hits.hits.total: 2}

server/src/main/java/org/elasticsearch/ExceptionsHelper.java

@@ -308,13 +308,8 @@ public final class ExceptionsHelper {
                 }
             }
             this.index = indexName;
-            if (cause == null) {
-                this.reason = failure.reason();
-                this.causeType = null;
-            } else {
-                this.reason = cause.getMessage();
-                this.causeType = cause.getClass();
-            }
+            this.reason = cause.getMessage();
+            this.causeType = cause.getClass();
         }
 
         @Override

server/src/main/java/org/elasticsearch/action/ShardOperationFailedException.java

@@ -19,39 +19,70 @@
 
 package org.elasticsearch.action;
 
+import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.io.stream.Streamable;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.rest.RestStatus;
 
+import java.util.Objects;
+
 /**
  * An exception indicating that a failure occurred performing an operation on the shard.
  *
- *
  */
-public interface ShardOperationFailedException extends Streamable, ToXContent {
+public abstract class ShardOperationFailedException implements Streamable, ToXContent {
+
+    protected String index;
+    protected int shardId;
+    protected String reason;
+    protected RestStatus status;
+    protected Throwable cause;
+
+    protected ShardOperationFailedException() {
+
+    }
+
+    protected ShardOperationFailedException(@Nullable String index, int shardId, String reason, RestStatus status, Throwable cause) {
+        this.index = index;
+        this.shardId = shardId;
+        this.reason = Objects.requireNonNull(reason, "reason cannot be null");
+        this.status = Objects.requireNonNull(status, "status cannot be null");
+        this.cause = Objects.requireNonNull(cause, "cause cannot be null");
+    }
 
     /**
      * The index the operation failed on. Might return {@code null} if it can't be derived.
      */
-    String index();
+    @Nullable
+    public final String index() {
+        return index;
+    }
 
     /**
      * The index the operation failed on. Might return {@code -1} if it can't be derived.
      */
-    int shardId();
+    public final int shardId() {
+        return shardId;
+    }
 
     /**
      * The reason of the failure.
      */
-    String reason();
+    public final String reason() {
+        return reason;
+    }
 
     /**
      * The status of the failure.
      */
-    RestStatus status();
+    public final RestStatus status() {
+        return status;
+    }
 
     /**
      * The cause of this failure
      */
-    Throwable getCause();
+    public final Throwable getCause() {
+        return cause;
+    }
 }

server/src/main/java/org/elasticsearch/action/admin/indices/shards/IndicesShardStoresResponse.java

@@ -21,7 +21,6 @@ package org.elasticsearch.action.admin.indices.shards;
 
 import com.carrotsearch.hppc.cursors.IntObjectCursor;
 import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
-
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionResponse;
@@ -248,7 +247,7 @@ public class IndicesShardStoresResponse extends ActionResponse implements ToXCon
             return nodeId;
         }
 
-        public static Failure readFailure(StreamInput in) throws IOException {
+        static Failure readFailure(StreamInput in) throws IOException {
             Failure failure = new Failure();
             failure.readFrom(in);
             return failure;

server/src/main/java/org/elasticsearch/action/search/SearchPhaseExecutionException.java

@@ -138,8 +138,7 @@ public class SearchPhaseExecutionException extends ElasticsearchException {
         builder.field("grouped", group); // notify that it's grouped
         builder.field("failed_shards");
         builder.startArray();
-        ShardOperationFailedException[] failures = params.paramAsBoolean("group_shard_failures", true) ?
-                ExceptionsHelper.groupBy(shardFailures) : shardFailures;
+        ShardOperationFailedException[] failures = group ? ExceptionsHelper.groupBy(shardFailures) : shardFailures;
         for (ShardOperationFailedException failure : failures) {
             builder.startObject();
             failure.toXContent(builder, params);

server/src/main/java/org/elasticsearch/action/search/ShardSearchFailure.java

@@ -43,7 +43,7 @@ import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpect
 /**
  * Represents a failure to search on a specific shard.
  */
-public class ShardSearchFailure implements ShardOperationFailedException {
+public class ShardSearchFailure extends ShardOperationFailedException {
 
     private static final String REASON_FIELD = "reason";
     private static final String NODE_FIELD = "node";
@@ -53,9 +53,6 @@ public class ShardSearchFailure implements ShardOperationFailedException {
     public static final ShardSearchFailure[] EMPTY_ARRAY = new ShardSearchFailure[0];
 
     private SearchShardTarget shardTarget;
-    private String reason;
-    private RestStatus status;
-    private Throwable cause;
 
     private ShardSearchFailure() {
 
@@ -66,25 +63,18 @@ public class ShardSearchFailure implements ShardOperationFailedException {
     }
 
     public ShardSearchFailure(Exception e, @Nullable SearchShardTarget shardTarget) {
+        super(shardTarget == null ? null : shardTarget.getFullyQualifiedIndexName(),
+            shardTarget == null ? -1 : shardTarget.getShardId().getId(),
+            ExceptionsHelper.detailedMessage(e),
+            ExceptionsHelper.status(ExceptionsHelper.unwrapCause(e)),
+            ExceptionsHelper.unwrapCause(e));
+
         final Throwable actual = ExceptionsHelper.unwrapCause(e);
         if (actual instanceof SearchException) {
             this.shardTarget = ((SearchException) actual).shard();
         } else if (shardTarget != null) {
             this.shardTarget = shardTarget;
         }
-        status = ExceptionsHelper.status(actual);
-        this.reason = ExceptionsHelper.detailedMessage(e);
-        this.cause = actual;
-    }
-
-    public ShardSearchFailure(String reason, SearchShardTarget shardTarget) {
-        this(reason, shardTarget, RestStatus.INTERNAL_SERVER_ERROR);
-    }
-
-    private ShardSearchFailure(String reason, SearchShardTarget shardTarget, RestStatus status) {
-        this.shardTarget = shardTarget;
-        this.reason = reason;
-        this.status = status;
     }
 
     /**
@@ -95,41 +85,6 @@ public class ShardSearchFailure implements ShardOperationFailedException {
         return this.shardTarget;
     }
 
-    @Override
-    public RestStatus status() {
-        return this.status;
-    }
-
-    /**
-     * The index the search failed on.
-     */
-    @Override
-    public String index() {
-        if (shardTarget != null) {
-            return shardTarget.getFullyQualifiedIndexName();
-        }
-        return null;
-    }
-
-    /**
-     * The shard id the search failed on.
-     */
-    @Override
-    public int shardId() {
-        if (shardTarget != null) {
-            return shardTarget.getShardId().id();
-        }
-        return -1;
-    }
-
-    /**
-     * The reason of the failure.
-     */
-    @Override
-    public String reason() {
-        return this.reason;
-    }
-
     @Override
     public String toString() {
         return "shard [" + (shardTarget == null ? "_na" : shardTarget) + "], reason [" + reason + "], cause [" +
@@ -172,12 +127,10 @@ public class ShardSearchFailure implements ShardOperationFailedException {
         if (shardTarget != null) {
             builder.field(NODE_FIELD, shardTarget.getNodeId());
         }
-        if (cause != null) {
-            builder.field(REASON_FIELD);
-            builder.startObject();
-            ElasticsearchException.generateThrowableXContent(builder, params, cause);
-            builder.endObject();
-        }
+        builder.field(REASON_FIELD);
+        builder.startObject();
+        ElasticsearchException.generateThrowableXContent(builder, params, cause);
+        builder.endObject();
         return builder;
     }
 
@@ -225,9 +178,4 @@ public class ShardSearchFailure implements ShardOperationFailedException {
         }
         return new ShardSearchFailure(exception, searchShardTarget);
     }
-
-    @Override
-    public Throwable getCause() {
-        return cause;
-    }
 }

server/src/main/java/org/elasticsearch/action/support/DefaultShardOperationFailedException.java

@@ -28,8 +28,6 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ConstructingObjectParser;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.index.Index;
-import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.rest.RestStatus;
 
 import java.io.IOException;
@@ -37,7 +35,7 @@ import java.io.IOException;
 import static org.elasticsearch.ExceptionsHelper.detailedMessage;
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
 
-public class DefaultShardOperationFailedException implements ShardOperationFailedException {
+public class DefaultShardOperationFailedException extends ShardOperationFailedException {
 
     private static final String INDEX = "index";
     private static final String SHARD_ID = "shard";
@@ -52,56 +50,16 @@ public class DefaultShardOperationFailedException implements ShardOperationFaile
         PARSER.declareObject(constructorArg(), (p, c) -> ElasticsearchException.fromXContent(p), new ParseField(REASON));
     }
 
-    private String index;
-
-    private int shardId;
-
-    private Throwable reason;
-
-    private RestStatus status;
-
     protected DefaultShardOperationFailedException() {
     }
 
     public DefaultShardOperationFailedException(ElasticsearchException e) {
-        Index index = e.getIndex();
-        this.index = index == null ? null : index.getName();
-        ShardId shardId = e.getShardId();
-        this.shardId = shardId == null ? -1 : shardId.id();
-        this.reason = e;
-        this.status = e.status();
+        super(e.getIndex() == null ? null : e.getIndex().getName(), e.getShardId() == null ? -1 : e.getShardId().getId(),
+            detailedMessage(e), e.status(), e);
     }
 
-    public DefaultShardOperationFailedException(String index, int shardId, Throwable reason) {
-        this.index = index;
-        this.shardId = shardId;
-        this.reason = reason;
-        this.status = ExceptionsHelper.status(reason);
-    }
-
-    @Override
-    public String index() {
-        return this.index;
-    }
-
-    @Override
-    public int shardId() {
-        return this.shardId;
-    }
-
-    @Override
-    public String reason() {
-        return detailedMessage(reason);
-    }
-
-    @Override
-    public RestStatus status() {
-        return status;
-    }
-
-    @Override
-    public Throwable getCause() {
-        return reason;
+    public DefaultShardOperationFailedException(String index, int shardId, Throwable cause) {
+        super(index, shardId, detailedMessage(cause), ExceptionsHelper.status(cause), cause);
     }
 
     public static DefaultShardOperationFailedException readShardOperationFailed(StreamInput in) throws IOException {
@@ -112,24 +70,17 @@ public class DefaultShardOperationFailedException implements ShardOperationFaile
 
     @Override
     public void readFrom(StreamInput in) throws IOException {
-        if (in.readBoolean()) {
-            index = in.readString();
-        }
+        index = in.readOptionalString();
         shardId = in.readVInt();
-        reason = in.readException();
+        cause = in.readException();
         status = RestStatus.readFrom(in);
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        if (index == null) {
-            out.writeBoolean(false);
-        } else {
-            out.writeBoolean(true);
-            out.writeString(index);
-        }
+        out.writeOptionalString(index);
         out.writeVInt(shardId);
-        out.writeException(reason);
+        out.writeException(cause);
         RestStatus.writeTo(out, status);
     }
 
@@ -145,7 +96,7 @@ public class DefaultShardOperationFailedException implements ShardOperationFaile
         builder.field("status", status.name());
         if (reason != null) {
             builder.startObject("reason");
-            ElasticsearchException.generateThrowableXContent(builder, params, reason);
+            ElasticsearchException.generateThrowableXContent(builder, params, cause);
             builder.endObject();
         }
         return builder;

server/src/main/java/org/elasticsearch/action/support/replication/ReplicationResponse.java

@@ -218,13 +218,13 @@ public class ReplicationResponse extends ActionResponse {
                 '}';
         }
 
-        public static ShardInfo readShardInfo(StreamInput in) throws IOException {
+        static ShardInfo readShardInfo(StreamInput in) throws IOException {
             ShardInfo shardInfo = new ShardInfo();
             shardInfo.readFrom(in);
             return shardInfo;
         }
 
-        public static class Failure implements ShardOperationFailedException, ToXContentObject {
+        public static class Failure extends ShardOperationFailedException implements ToXContentObject {
 
             private static final String _INDEX = "_index";
             private static final String _SHARD = "_shard";
@@ -235,37 +235,18 @@ public class ReplicationResponse extends ActionResponse {
 
             private ShardId shardId;
             private String nodeId;
-            private Exception cause;
-            private RestStatus status;
             private boolean primary;
 
             public Failure(ShardId  shardId, @Nullable String nodeId, Exception cause, RestStatus status, boolean primary) {
+                super(shardId.getIndexName(), shardId.getId(), ExceptionsHelper.detailedMessage(cause), status, cause);
                 this.shardId = shardId;
                 this.nodeId = nodeId;
-                this.cause = cause;
-                this.status = status;
                 this.primary = primary;
             }
 
             Failure() {
             }
 
-            /**
-             * @return On what index the failure occurred.
-             */
-            @Override
-            public String index() {
-                return shardId.getIndexName();
-            }
-
-            /**
-             * @return On what shard id the failure occurred.
-             */
-            @Override
-            public int shardId() {
-                return shardId.id();
-            }
-
             public ShardId fullShardId() {
                 return shardId;
             }
@@ -278,27 +259,6 @@ public class ReplicationResponse extends ActionResponse {
                 return nodeId;
             }
 
-            /**
-             * @return A text description of the failure
-             */
-            @Override
-            public String reason() {
-                return ExceptionsHelper.detailedMessage(cause);
-            }
-
-            /**
-             * @return The status to report if this failure was a primary failure.
-             */
-            @Override
-            public RestStatus status() {
-                return status;
-            }
-
-            @Override
-            public Throwable getCause() {
-                return cause;
-            }
-
             /**
              * @return Whether this failure occurred on a primary shard.
              * (this only reports true for delete by query)
@@ -310,6 +270,8 @@ public class ReplicationResponse extends ActionResponse {
             @Override
             public void readFrom(StreamInput in) throws IOException {
                 shardId = ShardId.readShardId(in);
+                super.shardId = shardId.getId();
+                super.index = shardId.getIndexName();
                 nodeId = in.readOptionalString();
                 cause = in.readException();
                 status = RestStatus.readFrom(in);

server/src/main/java/org/elasticsearch/index/mapper/IndexFieldMapper.java

@@ -126,7 +126,7 @@ public class IndexFieldMapper extends MetadataFieldMapper {
          */
         @Override
         public Query termQuery(Object value, @Nullable QueryShardContext context) {
-            if (isSameIndex(value, context.getFullyQualifiedIndexName())) {
+            if (isSameIndex(value, context.getFullyQualifiedIndex().getName())) {
                 return Queries.newMatchAllQuery();
             } else {
                 return Queries.newMatchNoDocsQuery("Index didn't match. Index queried: " + context.index().getName() + " vs. " + value);
@@ -139,14 +139,14 @@ public class IndexFieldMapper extends MetadataFieldMapper {
                 return super.termsQuery(values, context);
             }
             for (Object value : values) {
-                if (isSameIndex(value, context.getFullyQualifiedIndexName())) {
+                if (isSameIndex(value, context.getFullyQualifiedIndex().getName())) {
                     // No need to OR these clauses - we can only logically be
                     // running in the context of just one of these index names.
                     return Queries.newMatchAllQuery();
                 }
             }
             // None of the listed index names are this one
-            return Queries.newMatchNoDocsQuery("Index didn't match. Index queried: " + context.getFullyQualifiedIndexName()
+            return Queries.newMatchNoDocsQuery("Index didn't match. Index queried: " + context.getFullyQualifiedIndex().getName()
                 + " vs. " + values);
         }
 
@@ -189,5 +189,4 @@ public class IndexFieldMapper extends MetadataFieldMapper {
     protected void doMerge(Mapper mergeWith) {
         // nothing to do
     }
-
 }

server/src/main/java/org/elasticsearch/index/query/QueryShardContext.java

@@ -83,7 +83,7 @@ public class QueryShardContext extends QueryRewriteContext {
     private String[] types = Strings.EMPTY_ARRAY;
     private boolean cachable = true;
     private final SetOnce<Boolean> frozen = new SetOnce<>();
-    private final String fullyQualifiedIndexName;
+    private final Index fullyQualifiedIndex;
 
     public void setTypes(String... types) {
         this.types = types;
@@ -116,7 +116,8 @@ public class QueryShardContext extends QueryRewriteContext {
         this.indexSettings = indexSettings;
         this.reader = reader;
         this.clusterAlias = clusterAlias;
-        this.fullyQualifiedIndexName = RemoteClusterAware.buildRemoteIndexName(clusterAlias, indexSettings.getIndex().getName());
+        this.fullyQualifiedIndex = new Index(RemoteClusterAware.buildRemoteIndexName(clusterAlias, indexSettings.getIndex().getName()),
+            indexSettings.getIndex().getUUID());
     }
 
     public QueryShardContext(QueryShardContext source) {
@@ -163,7 +164,7 @@ public class QueryShardContext extends QueryRewriteContext {
     }
 
     public <IFD extends IndexFieldData<?>> IFD getForField(MappedFieldType fieldType) {
-        return (IFD) indexFieldDataService.apply(fieldType, fullyQualifiedIndexName);
+        return (IFD) indexFieldDataService.apply(fieldType, fullyQualifiedIndex.getName());
     }
 
     public void addNamedQuery(String name, Query query) {
@@ -275,7 +276,7 @@ public class QueryShardContext extends QueryRewriteContext {
     public SearchLookup lookup() {
         if (lookup == null) {
             lookup = new SearchLookup(getMapperService(),
-                mappedFieldType -> indexFieldDataService.apply(mappedFieldType, fullyQualifiedIndexName), types);
+                mappedFieldType -> indexFieldDataService.apply(mappedFieldType, fullyQualifiedIndex.getName()), types);
         }
         return lookup;
     }
@@ -426,9 +427,9 @@ public class QueryShardContext extends QueryRewriteContext {
     }
 
     /**
-     * Returns the fully qualified index name including a remote cluster alias if applicable
+     * Returns the fully qualified index including a remote cluster alias if applicable, and the index uuid
      */
-    public String getFullyQualifiedIndexName() {
-        return fullyQualifiedIndexName;
+    public Index getFullyQualifiedIndex() {
+        return fullyQualifiedIndex;
     }
 }

server/src/main/java/org/elasticsearch/index/query/QueryShardException.java

@@ -37,16 +37,15 @@ public class QueryShardException extends ElasticsearchException {
     }
 
     public QueryShardException(QueryShardContext context, String msg, Throwable cause, Object... args) {
-        super(msg, cause, args);
-        setIndex(context.getFullyQualifiedIndexName());
+        this(context.getFullyQualifiedIndex(), msg, cause, args);
     }
 
     /**
      * This constructor is provided for use in unit tests where a
      * {@link QueryShardContext} may not be available
      */
-    public QueryShardException(Index index, String msg, Throwable cause) {
-        super(msg, cause);
+    public QueryShardException(Index index, String msg, Throwable cause, Object... args) {
+        super(msg, cause, args);
         setIndex(index);
     }
 

server/src/main/java/org/elasticsearch/index/seqno/ReplicationTracker.java

@@ -39,6 +39,7 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Objects;
 import java.util.OptionalLong;
 import java.util.Set;
 import java.util.function.Function;
@@ -127,6 +128,13 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
      */
     final Map<String, CheckpointState> checkpoints;
 
+    /**
+     * A callback invoked when the global checkpoint is updated. For primary mode this occurs if the computed global checkpoint advances on
+     * the basis of state changes tracked here. For non-primary mode this occurs if the local knowledge of the global checkpoint advances
+     * due to an update from the primary.
+     */
+    private final LongConsumer onGlobalCheckpointUpdated;
+
     /**
      * This set contains allocation IDs for which there is a thread actively waiting for the local checkpoint to advance to at least the
      * current global checkpoint.
@@ -391,7 +399,8 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
             final ShardId shardId,
             final String allocationId,
             final IndexSettings indexSettings,
-            final long globalCheckpoint) {
+            final long globalCheckpoint,
+            final LongConsumer onGlobalCheckpointUpdated) {
         super(shardId, indexSettings);
         assert globalCheckpoint >= SequenceNumbers.UNASSIGNED_SEQ_NO : "illegal initial global checkpoint: " + globalCheckpoint;
         this.shardAllocationId = allocationId;
@@ -400,6 +409,7 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
         this.appliedClusterStateVersion = -1L;
         this.checkpoints = new HashMap<>(1 + indexSettings.getNumberOfReplicas());
         checkpoints.put(allocationId, new CheckpointState(SequenceNumbers.UNASSIGNED_SEQ_NO, globalCheckpoint, false, false));
+        this.onGlobalCheckpointUpdated = Objects.requireNonNull(onGlobalCheckpointUpdated);
         this.pendingInSync = new HashSet<>();
         this.routingTable = null;
         this.replicationGroup = null;
@@ -456,7 +466,10 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
         updateGlobalCheckpoint(
                 shardAllocationId,
                 globalCheckpoint,
-                current -> logger.trace("updating global checkpoint from [{}] to [{}] due to [{}]", current, globalCheckpoint, reason));
+                current -> {
+                    logger.trace("updated global checkpoint from [{}] to [{}] due to [{}]", current, globalCheckpoint, reason);
+                    onGlobalCheckpointUpdated.accept(globalCheckpoint);
+                });
         assert invariant();
     }
 
@@ -474,7 +487,7 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
                 allocationId,
                 globalCheckpoint,
                 current -> logger.trace(
-                        "updating local knowledge for [{}] on the primary of the global checkpoint from [{}] to [{}]",
+                        "updated local knowledge for [{}] on the primary of the global checkpoint from [{}] to [{}]",
                         allocationId,
                         current,
                         globalCheckpoint));
@@ -485,8 +498,8 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
         final CheckpointState cps = checkpoints.get(allocationId);
         assert !this.shardAllocationId.equals(allocationId) || cps != null;
         if (cps != null && globalCheckpoint > cps.globalCheckpoint) {
-            ifUpdated.accept(cps.globalCheckpoint);
             cps.globalCheckpoint = globalCheckpoint;
+            ifUpdated.accept(cps.globalCheckpoint);
         }
     }
 
@@ -737,8 +750,9 @@ public class ReplicationTracker extends AbstractIndexShardComponent implements L
         assert computedGlobalCheckpoint >= globalCheckpoint : "new global checkpoint [" + computedGlobalCheckpoint +
             "] is lower than previous one [" + globalCheckpoint + "]";
         if (globalCheckpoint != computedGlobalCheckpoint) {
-            logger.trace("global checkpoint updated to [{}]", computedGlobalCheckpoint);
             cps.globalCheckpoint = computedGlobalCheckpoint;
+            logger.trace("updated global checkpoint to [{}]", computedGlobalCheckpoint);
+            onGlobalCheckpointUpdated.accept(computedGlobalCheckpoint);
         }
     }
 

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -297,8 +297,9 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
 
         this.checkIndexOnStartup = indexSettings.getValue(IndexSettings.INDEX_CHECK_ON_STARTUP);
         this.translogConfig = new TranslogConfig(shardId, shardPath().resolveTranslog(), indexSettings, bigArrays);
-        this.replicationTracker = new ReplicationTracker(shardId, shardRouting.allocationId().getId(), indexSettings,
-            SequenceNumbers.UNASSIGNED_SEQ_NO);
+        final String aId = shardRouting.allocationId().getId();
+        this.replicationTracker =
+                new ReplicationTracker(shardId, aId, indexSettings, SequenceNumbers.UNASSIGNED_SEQ_NO, globalCheckpoint -> {});
         // the query cache is a node-level thing, however we want the most popular filters
         // to be computed on a per-shard basis
         if (IndexModule.INDEX_QUERY_CACHE_EVERYTHING_SETTING.get(settings)) {
@@ -1446,10 +1447,10 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
             }
         } else {
             if (origin == Engine.Operation.Origin.PRIMARY) {
-                verifyPrimary();
+                assert assertPrimaryMode();
             } else {
                 assert origin == Engine.Operation.Origin.REPLICA;
-                verifyReplicationTarget();
+                assert assertReplicationTarget();
             }
             if (writeAllowedStates.contains(state) == false) {
                 throw new IllegalIndexShardStateException(shardId, state, "operation only allowed when shard state is one of " + writeAllowedStates + ", origin [" + origin + "]");
@@ -1457,19 +1458,14 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
         }
     }
 
-    private void verifyPrimary() {
-        if (shardRouting.primary() == false) {
-            throw new IllegalStateException("shard " + shardRouting + " is not a primary");
-        }
+    private boolean assertPrimaryMode() {
+        assert shardRouting.primary() && replicationTracker.isPrimaryMode() : "shard " + shardRouting + " is not a primary shard in primary mode";
+        return true;
     }
 
-    private void verifyReplicationTarget() {
-        final IndexShardState state = state();
-        if (shardRouting.primary() && shardRouting.active() && replicationTracker.isPrimaryMode()) {
-            // must use exception that is not ignored by replication logic. See TransportActions.isShardNotAvailableException
-            throw new IllegalStateException("active primary shard " + shardRouting + " cannot be a replication target before " +
-                "relocation hand off, state is [" + state + "]");
-        }
+    private boolean assertReplicationTarget() {
+        assert replicationTracker.isPrimaryMode() == false : "shard " + shardRouting + " in primary mode cannot be a replication target";
+        return true;
     }
 
     private void verifyNotClosed() throws IllegalIndexShardStateException {
@@ -1716,7 +1712,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @param checkpoint   the local checkpoint for the shard
      */
     public void updateLocalCheckpointForShard(final String allocationId, final long checkpoint) {
-        verifyPrimary();
+        assert assertPrimaryMode();
         verifyNotClosed();
         replicationTracker.updateLocalCheckpoint(allocationId, checkpoint);
     }
@@ -1728,7 +1724,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @param globalCheckpoint the global checkpoint
      */
     public void updateGlobalCheckpointForShard(final String allocationId, final long globalCheckpoint) {
-        verifyPrimary();
+        assert assertPrimaryMode();
         verifyNotClosed();
         replicationTracker.updateGlobalCheckpointForShard(allocationId, globalCheckpoint);
     }
@@ -1750,7 +1746,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @param allocationId  the allocation ID of the shard for which recovery was initiated
      */
     public void initiateTracking(final String allocationId) {
-        verifyPrimary();
+        assert assertPrimaryMode();
         replicationTracker.initiateTracking(allocationId);
     }
 
@@ -1763,7 +1759,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @param localCheckpoint the current local checkpoint on the shard
      */
     public void markAllocationIdAsInSync(final String allocationId, final long localCheckpoint) throws InterruptedException {
-        verifyPrimary();
+        assert assertPrimaryMode();
         replicationTracker.markAllocationIdAsInSync(allocationId, localCheckpoint);
     }
 
@@ -1798,7 +1794,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @return a map from allocation ID to the local knowledge of the global checkpoint for that allocation ID
      */
     public ObjectLongMap<String> getInSyncGlobalCheckpoints() {
-        verifyPrimary();
+        assert assertPrimaryMode();
         verifyNotClosed();
         return replicationTracker.getInSyncGlobalCheckpoints();
     }
@@ -1808,11 +1804,12 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * primary.
      */
     public void maybeSyncGlobalCheckpoint(final String reason) {
-        verifyPrimary();
         verifyNotClosed();
+        assert shardRouting.primary() : "only call maybeSyncGlobalCheckpoint on primary shard";
         if (replicationTracker.isPrimaryMode() == false) {
             return;
         }
+        assert assertPrimaryMode();
         // only sync if there are not operations in flight
         final SeqNoStats stats = getEngine().getSeqNoStats(replicationTracker.getGlobalCheckpoint());
         if (stats.getMaxSeqNo() == stats.getGlobalCheckpoint()) {
@@ -1838,7 +1835,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @return the replication group
      */
     public ReplicationGroup getReplicationGroup() {
-        verifyPrimary();
+        assert assertPrimaryMode();
         verifyNotClosed();
         return replicationTracker.getReplicationGroup();
     }
@@ -1850,7 +1847,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @param reason           the reason the global checkpoint was updated
      */
     public void updateGlobalCheckpointOnReplica(final long globalCheckpoint, final String reason) {
-        verifyReplicationTarget();
+        assert assertReplicationTarget();
         final long localCheckpoint = getLocalCheckpoint();
         if (globalCheckpoint > localCheckpoint) {
             /*
@@ -1877,8 +1874,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @param primaryContext the sequence number context
      */
     public void activateWithPrimaryContext(final ReplicationTracker.PrimaryContext primaryContext) {
-        verifyPrimary();
-        assert shardRouting.isRelocationTarget() : "only relocation target can update allocation IDs from primary context: " + shardRouting;
+        assert shardRouting.primary() && shardRouting.isRelocationTarget() : "only primary relocation target can update allocation IDs from primary context: " + shardRouting;
         assert primaryContext.getCheckpointStates().containsKey(routingEntry().allocationId().getId()) &&
             getLocalCheckpoint() == primaryContext.getCheckpointStates().get(routingEntry().allocationId().getId()).getLocalCheckpoint();
         synchronized (mutex) {
@@ -1892,7 +1888,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      * @return {@code true} if there is at least one shard pending in-sync, otherwise false
      */
     public boolean pendingInSync() {
-        verifyPrimary();
+        assert assertPrimaryMode();
         return replicationTracker.pendingInSync();
     }
 
@@ -2209,7 +2205,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
      */
     public void acquirePrimaryOperationPermit(ActionListener<Releasable> onPermitAcquired, String executorOnDelay, Object debugInfo) {
         verifyNotClosed();
-        verifyPrimary();
+        assert shardRouting.primary() : "acquirePrimaryOperationPermit should only be called on primary shard: " + shardRouting;
 
         indexShardOperationPermits.acquire(onPermitAcquired, executorOnDelay, false, debugInfo);
     }
@@ -2259,7 +2255,6 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
                                               final ActionListener<Releasable> onPermitAcquired, final String executorOnDelay,
                                               final Object debugInfo) {
         verifyNotClosed();
-        verifyReplicationTarget();
         if (opPrimaryTerm > pendingPrimaryTerm) {
             synchronized (mutex) {
                 if (opPrimaryTerm > pendingPrimaryTerm) {
@@ -2312,6 +2307,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
                                     operationPrimaryTerm);
                             onPermitAcquired.onFailure(new IllegalStateException(message));
                         } else {
+                            assert assertReplicationTarget();
                             try {
                                 updateGlobalCheckpointOnReplica(globalCheckpoint, "operation");
                             } catch (Exception e) {

server/src/main/java/org/elasticsearch/plugins/SearchPlugin.java

@@ -48,6 +48,7 @@ import org.elasticsearch.search.fetch.FetchSubPhase;
 import org.elasticsearch.search.fetch.subphase.highlight.Highlighter;
 import org.elasticsearch.search.rescore.RescorerBuilder;
 import org.elasticsearch.search.rescore.Rescorer;
+import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.Suggester;
 import org.elasticsearch.search.suggest.SuggestionBuilder;
 
@@ -149,31 +150,61 @@ public interface SearchPlugin {
      * Specification for a {@link Suggester}.
      */
     class SuggesterSpec<T extends SuggestionBuilder<T>> extends SearchExtensionSpec<T, CheckedFunction<XContentParser, T, IOException>> {
+
+        private Writeable.Reader<? extends Suggest.Suggestion> suggestionReader;
+
         /**
          * Specification of custom {@link Suggester}.
          *
          * @param name holds the names by which this suggester might be parsed. The {@link ParseField#getPreferredName()} is special as it
-         *        is the name by under which the reader is registered. So it is the name that the query should use as its
-         *        {@link NamedWriteable#getWriteableName()} too.
-         * @param reader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
+         *        is the name by under which the request builder and Suggestion response readers are registered. So it is the name that the
+         *        query and Suggestion response should use as their {@link NamedWriteable#getWriteableName()} return values too.
+         * @param builderReader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
          *        {@link StreamInput}
-         * @param parser the parser the reads the query suggester from xcontent
+         * @param builderParser a parser that reads the suggester's builder from xcontent
+         * @param suggestionReader the reader registered for this suggester's Suggestion response. Typically a reference to a constructor
+         *        that takes a {@link StreamInput}
          */
-        public SuggesterSpec(ParseField name, Writeable.Reader<T> reader, CheckedFunction<XContentParser, T, IOException> parser) {
-            super(name, reader, parser);
+        public SuggesterSpec(
+                ParseField name,
+                Writeable.Reader<T> builderReader,
+                CheckedFunction<XContentParser, T, IOException> builderParser,
+                Writeable.Reader<? extends Suggest.Suggestion> suggestionReader) {
+
+            super(name, builderReader, builderParser);
+            setSuggestionReader(suggestionReader);
         }
 
         /**
          * Specification of custom {@link Suggester}.
          *
-         * @param name the name by which this suggester might be parsed or deserialized. Make sure that the query builder returns this name
-         *        for {@link NamedWriteable#getWriteableName()}.
-         * @param reader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
+         * @param name the name by which this suggester might be parsed or deserialized. Make sure that the query builder and Suggestion
+         *        response reader return this name for {@link NamedWriteable#getWriteableName()}.
+         * @param builderReader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
          *        {@link StreamInput}
-         * @param parser the parser the reads the suggester builder from xcontent
+         * @param builderParser a parser that reads the suggester's builder from xcontent
+         * @param suggestionReader the reader registered for this suggester's Suggestion response. Typically a reference to a constructor
+         *        that takes a {@link StreamInput}
          */
-        public SuggesterSpec(String name, Writeable.Reader<T> reader, CheckedFunction<XContentParser, T, IOException> parser) {
-            super(name, reader, parser);
+        public SuggesterSpec(
+                String name,
+                Writeable.Reader<T> builderReader,
+                CheckedFunction<XContentParser, T, IOException> builderParser,
+                Writeable.Reader<? extends Suggest.Suggestion> suggestionReader) {
+
+            super(name, builderReader, builderParser);
+            setSuggestionReader(suggestionReader);
+        }
+
+        private void setSuggestionReader(Writeable.Reader<? extends Suggest.Suggestion> reader) {
+            this.suggestionReader = reader;
+        }
+
+        /**
+         * Returns the reader used to read the {@link Suggest.Suggestion} generated by this suggester
+         */
+        public Writeable.Reader<? extends Suggest.Suggestion> getSuggestionReader() {
+            return this.suggestionReader;
         }
     }
 

server/src/main/java/org/elasticsearch/search/SearchModule.java

@@ -247,13 +247,17 @@ import org.elasticsearch.search.sort.GeoDistanceSortBuilder;
 import org.elasticsearch.search.sort.ScoreSortBuilder;
 import org.elasticsearch.search.sort.ScriptSortBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
+import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.SuggestionBuilder;
+import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
 import org.elasticsearch.search.suggest.completion.CompletionSuggestionBuilder;
 import org.elasticsearch.search.suggest.phrase.Laplace;
 import org.elasticsearch.search.suggest.phrase.LinearInterpolation;
+import org.elasticsearch.search.suggest.phrase.PhraseSuggestion;
 import org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder;
 import org.elasticsearch.search.suggest.phrase.SmoothingModel;
 import org.elasticsearch.search.suggest.phrase.StupidBackoff;
+import org.elasticsearch.search.suggest.term.TermSuggestion;
 import org.elasticsearch.search.suggest.term.TermSuggestionBuilder;
 
 import java.util.ArrayList;
@@ -590,9 +594,14 @@ public class SearchModule {
     private void registerSuggesters(List<SearchPlugin> plugins) {
         registerSmoothingModels(namedWriteables);
 
-        registerSuggester(new SuggesterSpec<>("term", TermSuggestionBuilder::new, TermSuggestionBuilder::fromXContent));
-        registerSuggester(new SuggesterSpec<>("phrase", PhraseSuggestionBuilder::new, PhraseSuggestionBuilder::fromXContent));
-        registerSuggester(new SuggesterSpec<>("completion", CompletionSuggestionBuilder::new, CompletionSuggestionBuilder::fromXContent));
+        registerSuggester(new SuggesterSpec<>(TermSuggestionBuilder.SUGGESTION_NAME,
+            TermSuggestionBuilder::new, TermSuggestionBuilder::fromXContent, TermSuggestion::new));
+
+        registerSuggester(new SuggesterSpec<>(PhraseSuggestionBuilder.SUGGESTION_NAME,
+            PhraseSuggestionBuilder::new, PhraseSuggestionBuilder::fromXContent, PhraseSuggestion::new));
+
+        registerSuggester(new SuggesterSpec<>(CompletionSuggestionBuilder.SUGGESTION_NAME,
+            CompletionSuggestionBuilder::new, CompletionSuggestionBuilder::fromXContent, CompletionSuggestion::new));
 
         registerFromPlugin(plugins, SearchPlugin::getSuggesters, this::registerSuggester);
     }
@@ -602,6 +611,10 @@ public class SearchModule {
                 SuggestionBuilder.class, suggester.getName().getPreferredName(), suggester.getReader()));
         namedXContents.add(new NamedXContentRegistry.Entry(SuggestionBuilder.class, suggester.getName(),
                 suggester.getParser()));
+
+        namedWriteables.add(new NamedWriteableRegistry.Entry(
+            Suggest.Suggestion.class, suggester.getName().getPreferredName(), suggester.getSuggestionReader()
+        ));
     }
 
     private Map<String, Highlighter> setupHighlighters(Settings settings, List<SearchPlugin> plugins) {

server/src/main/java/org/elasticsearch/search/collapse/CollapseBuilder.java

@@ -247,6 +247,6 @@ public class CollapseBuilder implements Writeable, ToXContentObject {
                 + field + "`, " + "only indexed field can retrieve `inner_hits`");
         }
 
-        return new CollapseContext(fieldType, innerHits);
+        return new CollapseContext(field, fieldType, innerHits);
     }
 }

server/src/main/java/org/elasticsearch/search/collapse/CollapseContext.java

@@ -25,26 +25,31 @@ import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.NumberFieldMapper;
 import org.elasticsearch.index.query.InnerHitBuilder;
 
-import java.util.Collections;
 import java.util.List;
 
 /**
  * Context used for field collapsing
  */
 public class CollapseContext {
+    private final String fieldName;
     private final MappedFieldType fieldType;
     private final List<InnerHitBuilder> innerHits;
 
-    public CollapseContext(MappedFieldType fieldType, InnerHitBuilder innerHit) {
-        this.fieldType = fieldType;
-        this.innerHits = Collections.singletonList(innerHit);
-    }
-
-    public CollapseContext(MappedFieldType fieldType, List<InnerHitBuilder> innerHits) {
+    public CollapseContext(String fieldName,
+                           MappedFieldType fieldType,
+                           List<InnerHitBuilder> innerHits) {
+        this.fieldName = fieldName;
         this.fieldType = fieldType;
         this.innerHits = innerHits;
     }
 
+    /**
+     * The requested field name to collapse on.
+     */
+    public String getFieldName() {
+        return fieldName;
+    }
+
     /** The field type used for collapsing **/
     public MappedFieldType getFieldType() {
         return fieldType;

server/src/main/java/org/elasticsearch/search/fetch/subphase/DocValueFieldsFetchSubPhase.java

@@ -61,7 +61,7 @@ public final class DocValueFieldsFetchSubPhase implements FetchSubPhase {
 
         if (context.collapse() != null) {
             // retrieve the `doc_value` associated with the collapse field
-            String name = context.collapse().getFieldType().name();
+            String name = context.collapse().getFieldName();
             if (context.docValueFieldsContext() == null) {
                 context.docValueFieldsContext(new DocValueFieldsContext(
                         Collections.singletonList(new FieldAndFormat(name, DocValueFieldsContext.USE_DEFAULT_FORMAT))));

server/src/main/java/org/elasticsearch/search/internal/InternalSearchResponse.java

@@ -50,7 +50,7 @@ public class InternalSearchResponse extends SearchResponseSections implements Wr
         super(
                 SearchHits.readSearchHits(in),
                 in.readBoolean() ? InternalAggregations.readAggregations(in) : null,
-                in.readBoolean() ? Suggest.readSuggest(in) : null,
+                in.readBoolean() ? new Suggest(in) : null,
                 in.readBoolean(),
                 in.readOptionalBoolean(),
                 in.readOptionalWriteable(SearchProfileShardResults::new),
@@ -62,7 +62,7 @@ public class InternalSearchResponse extends SearchResponseSections implements Wr
     public void writeTo(StreamOutput out) throws IOException {
         hits.writeTo(out);
         out.writeOptionalStreamable((InternalAggregations)aggregations);
-        out.writeOptionalStreamable(suggest);
+        out.writeOptionalWriteable(suggest);
         out.writeBoolean(timedOut);
         out.writeOptionalBoolean(terminatedEarly);
         out.writeOptionalWriteable(profileResults);

server/src/main/java/org/elasticsearch/search/query/QuerySearchResult.java

@@ -293,7 +293,7 @@ public final class QuerySearchResult extends SearchPhaseResult {
         pipelineAggregators = in.readNamedWriteableList(PipelineAggregator.class).stream().map(a -> (SiblingPipelineAggregator) a)
                 .collect(Collectors.toList());
         if (in.readBoolean()) {
-            suggest = Suggest.readSuggest(in);
+            suggest = new Suggest(in);
         }
         searchTimedOut = in.readBoolean();
         terminatedEarly = in.readOptionalBoolean();

server/src/main/java/org/elasticsearch/search/suggest/Suggest.java

@@ -20,18 +20,18 @@ package org.elasticsearch.search.suggest;
 
 import org.apache.lucene.util.CollectionUtil;
 import org.apache.lucene.util.SetOnce;
+import org.elasticsearch.Version;
 import org.elasticsearch.common.CheckedFunction;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.io.stream.NamedWriteable;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.common.io.stream.Streamable;
+import org.elasticsearch.common.io.stream.Writeable;
 import org.elasticsearch.common.text.Text;
-import org.elasticsearch.common.xcontent.ConstructingObjectParser;
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.ToXContentFragment;
-import org.elasticsearch.common.xcontent.ToXContentObject;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -53,16 +53,15 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
-import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
-import static org.elasticsearch.common.xcontent.ConstructingObjectParser.optionalConstructorArg;
 import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
 
 /**
  * Top level suggest result, containing the result for each suggestion.
  */
-public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? extends Option>>>, Streamable, ToXContentFragment {
+public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? extends Option>>>, Writeable, ToXContentFragment {
 
     public static final String NAME = "suggest";
 
@@ -92,6 +91,40 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
         this.hasScoreDocs = filter(CompletionSuggestion.class).stream().anyMatch(CompletionSuggestion::hasScoreDocs);
     }
 
+    public Suggest(StreamInput in) throws IOException {
+        // in older versions, Suggestion types were serialized as Streamable
+        if (in.getVersion().before(Version.V_7_0_0_alpha1)) {
+            final int size = in.readVInt();
+            suggestions = new ArrayList<>(size);
+            for (int i = 0; i < size; i++) {
+                Suggestion<? extends Entry<? extends Option>> suggestion;
+                final int type = in.readVInt();
+                switch (type) {
+                    case TermSuggestion.TYPE:
+                        suggestion = new TermSuggestion(in);
+                        break;
+                    case CompletionSuggestion.TYPE:
+                        suggestion = new CompletionSuggestion(in);
+                        break;
+                    case PhraseSuggestion.TYPE:
+                        suggestion = new PhraseSuggestion(in);
+                        break;
+                    default:
+                        throw new IllegalArgumentException("Unknown suggestion type with ordinal " + type);
+                }
+                suggestions.add(suggestion);
+            }
+        } else {
+            int suggestionCount = in.readVInt();
+            suggestions = new ArrayList<>(suggestionCount);
+            for (int i = 0; i < suggestionCount; i++) {
+                suggestions.add(in.readNamedWriteable(Suggestion.class));
+            }
+        }
+
+        hasScoreDocs = filter(CompletionSuggestion.class).stream().anyMatch(CompletionSuggestion::hasScoreDocs);
+    }
+
     @Override
     public Iterator<Suggestion<? extends Entry<? extends Option>>> iterator() {
         return suggestions.iterator();
@@ -125,42 +158,20 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
         return hasScoreDocs;
     }
 
-    @Override
-    public void readFrom(StreamInput in) throws IOException {
-        final int size = in.readVInt();
-        suggestions = new ArrayList<>(size);
-        for (int i = 0; i < size; i++) {
-            // TODO: remove these complicated generics
-            Suggestion<? extends Entry<? extends Option>> suggestion;
-            final int type = in.readVInt();
-            switch (type) {
-            case TermSuggestion.TYPE:
-                suggestion = new TermSuggestion();
-                break;
-            case CompletionSuggestion.TYPE:
-                suggestion = new CompletionSuggestion();
-                break;
-            case 2: // CompletionSuggestion.TYPE
-                throw new IllegalArgumentException("Completion suggester 2.x is not supported anymore");
-            case PhraseSuggestion.TYPE:
-                suggestion = new PhraseSuggestion();
-                break;
-            default:
-                suggestion = new Suggestion();
-                break;
-            }
-            suggestion.readFrom(in);
-            suggestions.add(suggestion);
-        }
-        hasScoreDocs = filter(CompletionSuggestion.class).stream().anyMatch(CompletionSuggestion::hasScoreDocs);
-    }
-
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        out.writeVInt(suggestions.size());
-        for (Suggestion<?> command : suggestions) {
-            out.writeVInt(command.getWriteableType());
-            command.writeTo(out);
+        // in older versions, Suggestion types were serialized as Streamable
+        if (out.getVersion().before(Version.V_7_0_0_alpha1)) {
+            out.writeVInt(suggestions.size());
+            for (Suggestion<?> command : suggestions) {
+                out.writeVInt(command.getWriteableType());
+                command.writeTo(out);
+            }
+        } else {
+            out.writeVInt(suggestions.size());
+            for (Suggestion<? extends Entry<? extends Option>> suggestion : suggestions) {
+                out.writeNamedWriteable(suggestion);
+            }
         }
     }
 
@@ -195,12 +206,6 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
         return new Suggest(suggestions);
     }
 
-    public static Suggest readSuggest(StreamInput in) throws IOException {
-        Suggest result = new Suggest();
-        result.readFrom(in);
-        return result;
-    }
-
     public static List<Suggestion<? extends Entry<? extends Option>>> reduce(Map<String, List<Suggest.Suggestion>> groupedSuggestions) {
         List<Suggestion<? extends Entry<? extends Option>>> reduced = new ArrayList<>(groupedSuggestions.size());
         for (java.util.Map.Entry<String, List<Suggestion>> unmergedResults : groupedSuggestions.entrySet()) {
@@ -232,10 +237,27 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
             .collect(Collectors.toList());
     }
 
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+        if (other == null || getClass() != other.getClass()) {
+            return false;
+        }
+
+        return Objects.equals(suggestions, ((Suggest) other).suggestions);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(suggestions);
+    }
+
     /**
      * The suggestion responses corresponding with the suggestions in the request.
      */
-    public static class Suggestion<T extends Suggestion.Entry> implements Iterable<T>, Streamable, ToXContentFragment {
+    public abstract static class Suggestion<T extends Suggestion.Entry> implements Iterable<T>, NamedWriteable, ToXContentFragment {
 
         private static final String NAME = "suggestion";
 
@@ -252,6 +274,24 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
             this.size = size; // The suggested term size specified in request, only used for merging shard responses
         }
 
+        public Suggestion(StreamInput in) throws IOException {
+            name = in.readString();
+            size = in.readVInt();
+
+            // this is a hack to work around slightly different serialization order of earlier versions of TermSuggestion
+            if (in.getVersion().before(Version.V_7_0_0_alpha1) && this instanceof TermSuggestion) {
+                TermSuggestion t = (TermSuggestion) this;
+                t.setSort(SortBy.readFromStream(in));
+            }
+
+            int entriesCount = in.readVInt();
+            entries.clear();
+            for (int i = 0; i < entriesCount; i++) {
+                T newEntry = newEntry(in);
+                entries.add(newEntry);
+            }
+        }
+
         public void addTerm(T entry) {
             entries.add(entry);
         }
@@ -259,20 +299,14 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
         /**
          * Returns a integer representing the type of the suggestion. This is used for
          * internal serialization over the network.
+         *
+         * This class is now serialized as a NamedWriteable and this method only remains for backwards compatibility
          */
-        public int getWriteableType() { // TODO remove this in favor of NamedWriteable
+        @Deprecated
+        public int getWriteableType() {
             return TYPE;
         }
 
-        /**
-         * Returns a string representing the type of the suggestion. This type is added to
-         * the suggestion name in the XContent response, so that it can later be used by
-         * REST clients to determine the internal type of the suggestion.
-         */
-        protected String getType() {
-            return NAME;
-        }
-
         @Override
         public Iterator<T> iterator() {
             return entries.iterator();
@@ -346,57 +380,67 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
             }
         }
 
-        @Override
-        public void readFrom(StreamInput in) throws IOException {
-            innerReadFrom(in);
-            int size = in.readVInt();
-            entries.clear();
-            for (int i = 0; i < size; i++) {
-                T newEntry = newEntry();
-                newEntry.readFrom(in);
-                entries.add(newEntry);
-            }
-        }
-
-        protected T newEntry() {
-            return (T)new Entry();
-        }
-
-
-        protected void innerReadFrom(StreamInput in) throws IOException {
-            name = in.readString();
-            size = in.readVInt();
-        }
+        protected abstract T newEntry();
+        protected abstract T newEntry(StreamInput in) throws IOException;
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
-            innerWriteTo(out);
+            out.writeString(name);
+            out.writeVInt(size);
+
+            // this is a hack to work around slightly different serialization order in older versions of TermSuggestion
+            if (out.getVersion().before(Version.V_7_0_0_alpha1) && this instanceof TermSuggestion) {
+                TermSuggestion termSuggestion = (TermSuggestion) this;
+                termSuggestion.getSort().writeTo(out);
+            }
+
             out.writeVInt(entries.size());
             for (Entry<?> entry : entries) {
                 entry.writeTo(out);
             }
         }
 
-        public void innerWriteTo(StreamOutput out) throws IOException {
-            out.writeString(name);
-            out.writeVInt(size);
-        }
+        @Override
+        public abstract String getWriteableName();
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
             if (params.paramAsBoolean(RestSearchAction.TYPED_KEYS_PARAM, false)) {
                 // Concatenates the type and the name of the suggestion (ex: completion#foo)
-                builder.startArray(String.join(Aggregation.TYPED_KEYS_DELIMITER, getType(), getName()));
+                builder.startArray(String.join(Aggregation.TYPED_KEYS_DELIMITER, getWriteableName(), getName()));
             } else {
                 builder.startArray(getName());
             }
             for (Entry<?> entry : entries) {
+                builder.startObject();
                 entry.toXContent(builder, params);
+                builder.endObject();
             }
             builder.endArray();
             return builder;
         }
 
+        @Override
+        public boolean equals(Object other) {
+            if (this == other) {
+                return true;
+            }
+
+            if (other == null || getClass() != other.getClass()) {
+                return false;
+            }
+
+            Suggestion otherSuggestion = (Suggestion) other;
+            return Objects.equals(name, otherSuggestion.name)
+                && Objects.equals(size, otherSuggestion.size)
+                && Objects.equals(entries, otherSuggestion.entries);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(name, size, entries);
+        }
+
         @SuppressWarnings("unchecked")
         public static Suggestion<? extends Entry<? extends Option>> fromXContent(XContentParser parser) throws IOException {
             ensureExpectedToken(XContentParser.Token.START_ARRAY, parser.currentToken(), parser::getTokenLocation);
@@ -417,7 +461,7 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
         /**
          * Represents a part from the suggest text with suggested options.
          */
-        public static class Entry<O extends Entry.Option> implements Iterable<O>, Streamable, ToXContentObject {
+        public abstract static class Entry<O extends Option> implements Iterable<O>, Writeable, ToXContentFragment {
 
             private static final String TEXT = "text";
             private static final String OFFSET = "offset";
@@ -436,7 +480,18 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
                 this.length = length;
             }
 
-            protected Entry() {
+            protected Entry() {}
+
+            public Entry(StreamInput in) throws IOException {
+                text = in.readText();
+                offset = in.readVInt();
+                length = in.readVInt();
+                int suggestedWords = in.readVInt();
+                options = new ArrayList<>(suggestedWords);
+                for (int j = 0; j < suggestedWords; j++) {
+                    O newOption = newOption(in);
+                    options.add(newOption);
+                }
             }
 
             public void addOption(O option) {
@@ -534,44 +589,27 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
 
             @Override
             public boolean equals(Object o) {
-                if (this == o) return true;
-                if (o == null || getClass() != o.getClass()) return false;
+                if (this == o) {
+                    return true;
+                }
+                if (o == null || getClass() != o.getClass()) {
+                    return false;
+                }
 
                 Entry<?> entry = (Entry<?>) o;
-
-                if (length != entry.length) return false;
-                if (offset != entry.offset) return false;
-                if (!this.text.equals(entry.text)) return false;
-
-                return true;
+                return Objects.equals(length, entry.length)
+                    && Objects.equals(offset, entry.offset)
+                    && Objects.equals(text, entry.text)
+                    && Objects.equals(options, entry.options);
             }
 
             @Override
             public int hashCode() {
-                int result = text.hashCode();
-                result = 31 * result + offset;
-                result = 31 * result + length;
-                return result;
+                return Objects.hash(text, offset, length, options);
             }
 
-            @Override
-            public void readFrom(StreamInput in) throws IOException {
-                text = in.readText();
-                offset = in.readVInt();
-                length = in.readVInt();
-                int suggestedWords = in.readVInt();
-                options = new ArrayList<>(suggestedWords);
-                for (int j = 0; j < suggestedWords; j++) {
-                    O newOption = newOption();
-                    newOption.readFrom(in);
-                    options.add(newOption);
-                }
-            }
-
-            @SuppressWarnings("unchecked")
-            protected O newOption(){
-                return (O) new Option();
-            }
+            protected abstract O newOption();
+            protected abstract O newOption(StreamInput in) throws IOException;
 
             @Override
             public void writeTo(StreamOutput out) throws IOException {
@@ -586,40 +624,29 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
 
             @Override
             public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-                builder.startObject();
                 builder.field(TEXT, text);
                 builder.field(OFFSET, offset);
                 builder.field(LENGTH, length);
                 builder.startArray(OPTIONS);
                 for (Option option : options) {
+                    builder.startObject();
                     option.toXContent(builder, params);
+                    builder.endObject();
                 }
                 builder.endArray();
-                builder.endObject();
                 return builder;
             }
 
-            private static ObjectParser<Entry<Option>, Void> PARSER = new ObjectParser<>("SuggestionEntryParser", true, Entry::new);
-
-            static {
-                declareCommonFields(PARSER);
-                PARSER.declareObjectArray(Entry::addOptions, (p,c) -> Option.fromXContent(p), new ParseField(OPTIONS));
-            }
-
             protected static void declareCommonFields(ObjectParser<? extends Entry<? extends Option>, Void> parser) {
                 parser.declareString((entry, text) -> entry.text = new Text(text), new ParseField(TEXT));
                 parser.declareInt((entry, offset) -> entry.offset = offset, new ParseField(OFFSET));
                 parser.declareInt((entry, length) -> entry.length = length, new ParseField(LENGTH));
             }
 
-            public static Entry<? extends Option> fromXContent(XContentParser parser) {
-                return PARSER.apply(parser, null);
-            }
-
             /**
              * Contains the suggested text with its document frequency and score.
              */
-            public static class Option implements Streamable, ToXContentObject {
+            public abstract static class Option implements Writeable, ToXContentFragment {
 
                 public static final ParseField TEXT = new ParseField("text");
                 public static final ParseField HIGHLIGHTED = new ParseField("highlighted");
@@ -646,7 +673,13 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
                     this(text, null, score);
                 }
 
-                public Option() {
+                public Option() {}
+
+                public Option(StreamInput in) throws IOException {
+                    text = in.readText();
+                    score = in.readFloat();
+                    highlighted = in.readOptionalText();
+                    collateMatch = in.readOptionalBoolean();
                 }
 
                 /**
@@ -683,14 +716,6 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
                     this.score = score;
                 }
 
-                @Override
-                public void readFrom(StreamInput in) throws IOException {
-                    text = in.readText();
-                    score = in.readFloat();
-                    highlighted = in.readOptionalText();
-                    collateMatch = in.readOptionalBoolean();
-                }
-
                 @Override
                 public void writeTo(StreamOutput out) throws IOException {
                     out.writeText(text);
@@ -701,45 +726,19 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
 
                 @Override
                 public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-                    builder.startObject();
-                    innerToXContent(builder, params);
-                    builder.endObject();
-                    return builder;
-                }
-
-                protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
                     builder.field(TEXT.getPreferredName(), text);
                     if (highlighted != null) {
                         builder.field(HIGHLIGHTED.getPreferredName(), highlighted);
                     }
+
                     builder.field(SCORE.getPreferredName(), score);
                     if (collateMatch != null) {
                         builder.field(COLLATE_MATCH.getPreferredName(), collateMatch.booleanValue());
                     }
+
                     return builder;
                 }
 
-                private static final ConstructingObjectParser<Option, Void> PARSER = new ConstructingObjectParser<>("SuggestOptionParser",
-                        true, args -> {
-                            Text text = new Text((String) args[0]);
-                            float score = (Float) args[1];
-                            String highlighted = (String) args[2];
-                            Text highlightedText = highlighted == null ? null : new Text(highlighted);
-                            Boolean collateMatch = (Boolean) args[3];
-                            return new Option(text, highlightedText, score, collateMatch);
-                        });
-
-                static {
-                    PARSER.declareString(constructorArg(), TEXT);
-                    PARSER.declareFloat(constructorArg(), SCORE);
-                    PARSER.declareString(optionalConstructorArg(), HIGHLIGHTED);
-                    PARSER.declareBoolean(optionalConstructorArg(), COLLATE_MATCH);
-                }
-
-                public static Option fromXContent(XContentParser parser) {
-                    return PARSER.apply(parser, null);
-                }
-
                 protected void mergeInto(Option otherOption) {
                     score = Math.max(score, otherOption.score);
                     if (otherOption.collateMatch != null) {
@@ -751,18 +750,25 @@ public class Suggest implements Iterable<Suggest.Suggestion<? extends Entry<? ex
                     }
                 }
 
+                /*
+                 * We consider options equal if they have the same text, even if their other fields may differ
+                 */
                 @Override
                 public boolean equals(Object o) {
-                    if (this == o) return true;
-                    if (o == null || getClass() != o.getClass()) return false;
+                    if (this == o) {
+                        return true;
+                    }
+                    if (o == null || getClass() != o.getClass()) {
+                        return false;
+                    }
 
                     Option that = (Option) o;
-                    return text.equals(that.text);
+                    return Objects.equals(text, that.text);
                 }
 
                 @Override
                 public int hashCode() {
-                    return text.hashCode();
+                    return Objects.hash(text);
                 }
             }
         }

server/src/main/java/org/elasticsearch/search/suggest/completion/CompletionSuggestion.java

@@ -66,8 +66,7 @@ import static org.elasticsearch.search.suggest.Suggest.COMPARATOR;
  */
 public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSuggestion.Entry> {
 
-    public static final String NAME = "completion";
-
+    @Deprecated
     public static final int TYPE = 4;
 
     private boolean skipDuplicates;
@@ -86,14 +85,18 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
         this.skipDuplicates = skipDuplicates;
     }
 
-    @Override
-    public void readFrom(StreamInput in) throws IOException {
-        super.readFrom(in);
+    public CompletionSuggestion(StreamInput in) throws IOException {
+        super(in);
         if (in.getVersion().onOrAfter(Version.V_6_1_0)) {
             skipDuplicates = in.readBoolean();
         }
     }
 
+    @Override
+    public String getWriteableName() {
+        return CompletionSuggestionBuilder.SUGGESTION_NAME;
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
@@ -121,6 +124,17 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
         return getOptions().size() > 0;
     }
 
+    @Override
+    public boolean equals(Object other) {
+        return super.equals(other)
+            && Objects.equals(skipDuplicates, ((CompletionSuggestion) other).skipDuplicates);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), skipDuplicates);
+    }
+
     public static CompletionSuggestion fromXContent(XContentParser parser, String name) throws IOException {
         CompletionSuggestion suggestion = new CompletionSuggestion(name, -1, false);
         parseEntries(parser, suggestion, CompletionSuggestion.Entry::fromXContent);
@@ -222,13 +236,13 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
     }
 
     @Override
-    protected String getType() {
-        return NAME;
+    protected Entry newEntry() {
+        return new Entry();
     }
 
     @Override
-    protected Entry newEntry() {
-        return new Entry();
+    protected Entry newEntry(StreamInput in) throws IOException {
+        return new Entry(in);
     }
 
     public static final class Entry extends Suggest.Suggestion.Entry<CompletionSuggestion.Entry.Option> {
@@ -237,7 +251,10 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
             super(text, offset, length);
         }
 
-        Entry() {
+        Entry() {}
+
+        public Entry(StreamInput in) throws IOException {
+            super(in);
         }
 
         @Override
@@ -245,6 +262,11 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
             return new Option();
         }
 
+        @Override
+        protected Option newOption(StreamInput in) throws IOException {
+            return new Option(in);
+        }
+
         private static ObjectParser<Entry, Void> PARSER = new ObjectParser<>("CompletionSuggestionEntryParser", true,
                 Entry::new);
 
@@ -274,6 +296,25 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
                 super();
             }
 
+            public Option(StreamInput in) throws IOException {
+                super(in);
+                this.doc = Lucene.readScoreDoc(in);
+                if (in.readBoolean()) {
+                    this.hit = SearchHit.readSearchHit(in);
+                }
+                int contextSize = in.readInt();
+                this.contexts = new LinkedHashMap<>(contextSize);
+                for (int i = 0; i < contextSize; i++) {
+                    String contextName = in.readString();
+                    int nContexts = in.readVInt();
+                    Set<CharSequence> contexts = new HashSet<>(nContexts);
+                    for (int j = 0; j < nContexts; j++) {
+                        contexts.add(in.readString());
+                    }
+                    this.contexts.put(contextName, contexts);
+                }
+            }
+
             @Override
             protected void mergeInto(Suggest.Suggestion.Entry.Option otherOption) {
                 // Completion suggestions are reduced by
@@ -302,7 +343,7 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
             }
 
             @Override
-            protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
+            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
                 builder.field(TEXT.getPreferredName(), getText());
                 if (hit != null) {
                     hit.toInnerXContent(builder, params);
@@ -375,26 +416,6 @@ public final class CompletionSuggestion extends Suggest.Suggestion<CompletionSug
                 return option;
             }
 
-            @Override
-            public void readFrom(StreamInput in) throws IOException {
-                super.readFrom(in);
-                this.doc = Lucene.readScoreDoc(in);
-                if (in.readBoolean()) {
-                    this.hit = SearchHit.readSearchHit(in);
-                }
-                int contextSize = in.readInt();
-                this.contexts = new LinkedHashMap<>(contextSize);
-                for (int i = 0; i < contextSize; i++) {
-                    String contextName = in.readString();
-                    int nContexts = in.readVInt();
-                    Set<CharSequence> contexts = new HashSet<>(nContexts);
-                    for (int j = 0; j < nContexts; j++) {
-                        contexts.add(in.readString());
-                    }
-                    this.contexts.put(contextName, contexts);
-                }
-            }
-
             @Override
             public void writeTo(StreamOutput out) throws IOException {
                 super.writeTo(out);

server/src/main/java/org/elasticsearch/search/suggest/completion/CompletionSuggestionBuilder.java

@@ -59,10 +59,12 @@ import java.util.Objects;
 public class CompletionSuggestionBuilder extends SuggestionBuilder<CompletionSuggestionBuilder> {
 
     private static final XContentType CONTEXT_BYTES_XCONTENT_TYPE = XContentType.JSON;
-    static final String SUGGESTION_NAME = "completion";
+
     static final ParseField CONTEXTS_FIELD = new ParseField("contexts", "context");
     static final ParseField SKIP_DUPLICATES_FIELD = new ParseField("skip_duplicates");
 
+    public static final String SUGGESTION_NAME = "completion";
+
     /**
      * {
      *     "field" : STRING

server/src/main/java/org/elasticsearch/search/suggest/phrase/PhraseSuggester.java

@@ -133,9 +133,9 @@ public final class PhraseSuggester extends Suggester<PhraseSuggestionContext> {
                     highlighted = new Text(spare.toString());
                 }
                 if (collatePrune) {
-                    resultEntry.addOption(new Suggestion.Entry.Option(phrase, highlighted, (float) (correction.score), collateMatch));
+                    resultEntry.addOption(new PhraseSuggestion.Entry.Option(phrase, highlighted, (float) (correction.score), collateMatch));
                 } else {
-                    resultEntry.addOption(new Suggestion.Entry.Option(phrase, highlighted, (float) (correction.score)));
+                    resultEntry.addOption(new PhraseSuggestion.Entry.Option(phrase, highlighted, (float) (correction.score)));
                 }
             }
         } else {

server/src/main/java/org/elasticsearch/search/suggest/phrase/PhraseSuggestion.java

@@ -23,41 +23,55 @@ import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.text.Text;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.ContextParser;
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.Suggest.Suggestion;
 
 import java.io.IOException;
+import java.util.Objects;
+
+import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
+import static org.elasticsearch.common.xcontent.ConstructingObjectParser.optionalConstructorArg;
 
 /**
  * Suggestion entry returned from the {@link PhraseSuggester}.
  */
 public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry> {
 
-    public static final String NAME = "phrase";
+    @Deprecated
     public static final int TYPE = 3;
 
-    public PhraseSuggestion() {
-    }
+    public PhraseSuggestion() {}
 
     public PhraseSuggestion(String name, int size) {
         super(name, size);
     }
 
+    public PhraseSuggestion(StreamInput in) throws IOException {
+        super(in);
+    }
+
+    @Override
+    public String getWriteableName() {
+        return PhraseSuggestionBuilder.SUGGESTION_NAME;
+    }
+
     @Override
     public int getWriteableType() {
         return TYPE;
     }
 
     @Override
-    protected String getType() {
-        return NAME;
+    protected Entry newEntry() {
+        return new Entry();
     }
 
     @Override
-    protected Entry newEntry() {
-        return new Entry();
+    protected Entry newEntry(StreamInput in) throws IOException {
+        return new Entry(in);
     }
 
     public static PhraseSuggestion fromXContent(XContentParser parser, String name) throws IOException {
@@ -66,7 +80,7 @@ public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry>
         return suggestion;
     }
 
-    public static class Entry extends Suggestion.Entry<Suggestion.Entry.Option> {
+    public static class Entry extends Suggestion.Entry<PhraseSuggestion.Entry.Option> {
 
         protected double cutoffScore = Double.MIN_VALUE;
 
@@ -75,7 +89,15 @@ public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry>
             this.cutoffScore = cutoffScore;
         }
 
-        Entry() {
+        public Entry(Text text, int offset, int length) {
+            super(text, offset, length);
+        }
+
+        Entry() {}
+
+        public Entry(StreamInput in) throws IOException {
+            super(in);
+            cutoffScore = in.readDouble();
         }
 
         /**
@@ -86,7 +108,7 @@ public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry>
         }
 
         @Override
-        protected void merge(Suggestion.Entry<Suggestion.Entry.Option> other) {
+        protected void merge(Suggestion.Entry<Option> other) {
             super.merge(other);
             // If the cluster contains both pre 0.90.4 and post 0.90.4 nodes then we'll see Suggestion.Entry
             // objects being merged with PhraseSuggestion.Entry objects.  We merge Suggestion.Entry objects
@@ -100,7 +122,7 @@ public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry>
         }
 
         @Override
-        public void addOption(Suggestion.Entry.Option option) {
+        public void addOption(Option option) {
             if (option.getScore() > this.cutoffScore) {
                 this.options.add(option);
             }
@@ -110,7 +132,8 @@ public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry>
 
         static {
             declareCommonFields(PARSER);
-            PARSER.declareObjectArray(Entry::addOptions, (p,c) -> Option.fromXContent(p), new ParseField(OPTIONS));
+            PARSER.declareObjectArray(Entry::addOptions, (ContextParser<Void, Option>) (p, c) -> Option.fromXContent(p),
+                    new ParseField(OPTIONS));
         }
 
         public static Entry fromXContent(XContentParser parser) {
@@ -118,9 +141,13 @@ public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry>
         }
 
         @Override
-        public void readFrom(StreamInput in) throws IOException {
-            super.readFrom(in);
-            cutoffScore = in.readDouble();
+        protected Option newOption() {
+            return new Option();
+        }
+
+        @Override
+        protected Option newOption(StreamInput in) throws IOException {
+            return new Option(in);
         }
 
         @Override
@@ -128,5 +155,56 @@ public class PhraseSuggestion extends Suggest.Suggestion<PhraseSuggestion.Entry>
             super.writeTo(out);
             out.writeDouble(cutoffScore);
         }
+
+        @Override
+        public boolean equals(Object other) {
+            return super.equals(other)
+                && Objects.equals(cutoffScore, ((Entry) other).cutoffScore);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(super.hashCode(), cutoffScore);
+        }
+
+        public static class Option extends Suggestion.Entry.Option {
+
+            public Option() {
+                super();
+            }
+
+            public Option(Text text, Text highlighted, float score, Boolean collateMatch) {
+                super(text, highlighted, score, collateMatch);
+            }
+
+            public Option(Text text, Text highlighted, float score) {
+                super(text, highlighted, score);
+            }
+
+            public Option(StreamInput in) throws IOException {
+                super(in);
+            }
+
+            private static final ConstructingObjectParser<Option, Void> PARSER = new ConstructingObjectParser<>("PhraseOptionParser",
+                true, args -> {
+                    Text text = new Text((String) args[0]);
+                    float score = (Float) args[1];
+                    String highlighted = (String) args[2];
+                    Text highlightedText = highlighted == null ? null : new Text(highlighted);
+                    Boolean collateMatch = (Boolean) args[3];
+                    return new Option(text, highlightedText, score, collateMatch);
+            });
+
+            static {
+                PARSER.declareString(constructorArg(), TEXT);
+                PARSER.declareFloat(constructorArg(), SCORE);
+                PARSER.declareString(optionalConstructorArg(), HIGHLIGHTED);
+                PARSER.declareBoolean(optionalConstructorArg(), COLLATE_MATCH);
+            }
+
+            public static Option fromXContent(XContentParser parser) {
+                    return PARSER.apply(parser, null);
+            }
+        }
     }
 }

server/src/main/java/org/elasticsearch/search/suggest/phrase/PhraseSuggestionBuilder.java

@@ -59,7 +59,7 @@ import java.util.Set;
  */
 public class PhraseSuggestionBuilder extends SuggestionBuilder<PhraseSuggestionBuilder> {
 
-    private static final String SUGGESTION_NAME = "phrase";
+    public static final String SUGGESTION_NAME = "phrase";
 
     protected static final ParseField MAXERRORS_FIELD = new ParseField("max_errors");
     protected static final ParseField RWE_LIKELIHOOD_FIELD = new ParseField("real_word_error_likelihood");

server/src/main/java/org/elasticsearch/search/suggest/term/TermSuggestion.java

@@ -19,6 +19,7 @@
 package org.elasticsearch.search.suggest.term;
 
 import org.elasticsearch.ElasticsearchException;
+import org.elasticsearch.Version;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
@@ -28,11 +29,13 @@ import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.suggest.SortBy;
+import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.Suggest.Suggestion;
 import org.elasticsearch.search.suggest.Suggest.Suggestion.Entry.Option;
 
 import java.io.IOException;
 import java.util.Comparator;
+import java.util.Objects;
 
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
 
@@ -41,22 +44,29 @@ import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constru
  */
 public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
 
-    public static final String NAME = "term";
+    @Deprecated
+    public static final int TYPE = 1;
 
     public static final Comparator<Suggestion.Entry.Option> SCORE = new Score();
     public static final Comparator<Suggestion.Entry.Option> FREQUENCY = new Frequency();
-    public static final int TYPE = 1;
 
     private SortBy sort;
 
-    public TermSuggestion() {
-    }
+    public TermSuggestion() {}
 
     public TermSuggestion(String name, int size, SortBy sort) {
         super(name, size);
         this.sort = sort;
     }
 
+    public TermSuggestion(StreamInput in) throws IOException {
+        super(in);
+
+        if (in.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            sort = SortBy.readFromStream(in);
+        }
+    }
+
     // Same behaviour as comparators in suggest module, but for SuggestedWord
     // Highest score first, then highest freq first, then lowest term first
     public static class Score implements Comparator<Suggestion.Entry.Option> {
@@ -103,9 +113,12 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
         return TYPE;
     }
 
-    @Override
-    protected String getType() {
-        return NAME;
+    public void setSort(SortBy sort) {
+        this.sort = sort;
+    }
+
+    public SortBy getSort() {
+        return sort;
     }
 
     @Override
@@ -121,15 +134,17 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
     }
 
     @Override
-    protected void innerReadFrom(StreamInput in) throws IOException {
-        super.innerReadFrom(in);
-        sort = SortBy.readFromStream(in);
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+
+        if (out.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            sort.writeTo(out);
+        }
     }
 
     @Override
-    public void innerWriteTo(StreamOutput out) throws IOException {
-        super.innerWriteTo(out);
-        sort.writeTo(out);
+    public String getWriteableName() {
+        return TermSuggestionBuilder.SUGGESTION_NAME;
     }
 
     public static TermSuggestion fromXContent(XContentParser parser, String name) throws IOException {
@@ -144,16 +159,35 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
         return new Entry();
     }
 
+    @Override
+    protected Entry newEntry(StreamInput in) throws IOException {
+        return new Entry(in);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        return super.equals(other)
+            && Objects.equals(sort, ((TermSuggestion) other).sort);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), sort);
+    }
+
     /**
      * Represents a part from the suggest text with suggested options.
      */
-    public static class Entry extends org.elasticsearch.search.suggest.Suggest.Suggestion.Entry<TermSuggestion.Entry.Option> {
+    public static class Entry extends Suggest.Suggestion.Entry<TermSuggestion.Entry.Option> {
 
         public Entry(Text text, int offset, int length) {
             super(text, offset, length);
         }
 
-        Entry() {
+        public Entry() {}
+
+        public Entry(StreamInput in) throws IOException {
+            super(in);
         }
 
         @Override
@@ -161,6 +195,11 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
             return new Option();
         }
 
+        @Override
+        protected Option newOption(StreamInput in) throws IOException {
+            return new Option(in);
+        }
+
         private static ObjectParser<Entry, Void> PARSER = new ObjectParser<>("TermSuggestionEntryParser", true, Entry::new);
 
         static {
@@ -175,7 +214,7 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
         /**
          * Contains the suggested text with its document frequency and score.
          */
-        public static class Option extends org.elasticsearch.search.suggest.Suggest.Suggestion.Entry.Option {
+        public static class Option extends Suggest.Suggestion.Entry.Option {
 
             public static final ParseField FREQ = new ParseField("freq");
 
@@ -186,6 +225,11 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
                 this.freq = freq;
             }
 
+            public Option(StreamInput in) throws IOException {
+                super(in);
+                freq = in.readVInt();
+            }
+
             @Override
             protected void mergeInto(Suggestion.Entry.Option otherOption) {
                 super.mergeInto(otherOption);
@@ -207,12 +251,6 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
                 return freq;
             }
 
-            @Override
-            public void readFrom(StreamInput in) throws IOException {
-                super.readFrom(in);
-                freq = in.readVInt();
-            }
-
             @Override
             public void writeTo(StreamOutput out) throws IOException {
                 super.writeTo(out);
@@ -220,8 +258,8 @@ public class TermSuggestion extends Suggestion<TermSuggestion.Entry> {
             }
 
             @Override
-            protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
-                builder = super.innerToXContent(builder, params);
+            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+                builder = super.toXContent(builder, params);
                 builder.field(FREQ.getPreferredName(), freq);
                 return builder;
             }

server/src/main/java/org/elasticsearch/search/suggest/term/TermSuggestionBuilder.java

@@ -67,7 +67,7 @@ import static org.elasticsearch.search.suggest.phrase.DirectCandidateGeneratorBu
  */
 public class TermSuggestionBuilder extends SuggestionBuilder<TermSuggestionBuilder> {
 
-    private static final String SUGGESTION_NAME = "term";
+    public static final String SUGGESTION_NAME = "term";
 
     private SuggestMode suggestMode = SuggestMode.MISSING;
     private float accuracy = DEFAULT_ACCURACY;

server/src/main/java/org/elasticsearch/snapshots/SnapshotShardFailure.java

@@ -40,15 +40,11 @@ import java.util.Objects;
 /**
  * Stores information about failures that occurred during shard snapshotting process
  */
-public class SnapshotShardFailure implements ShardOperationFailedException {
-    private ShardId shardId;
-
-    private String reason;
+public class SnapshotShardFailure extends ShardOperationFailedException {
 
     @Nullable
     private String nodeId;
-
-    private RestStatus status;
+    private ShardId shardId;
 
     private SnapshotShardFailure() {
 
@@ -74,56 +70,9 @@ public class SnapshotShardFailure implements ShardOperationFailedException {
      * @param status  rest status
      */
     private SnapshotShardFailure(@Nullable String nodeId, ShardId shardId, String reason, RestStatus status) {
-        assert reason != null;
+        super(shardId.getIndexName(), shardId.id(), reason, status, new IndexShardSnapshotFailedException(shardId, reason));
         this.nodeId = nodeId;
         this.shardId = shardId;
-        this.reason = reason;
-        this.status = status;
-    }
-
-    /**
-     * Returns index where failure occurred
-     *
-     * @return index
-     */
-    @Override
-    public String index() {
-        return this.shardId.getIndexName();
-    }
-
-    /**
-     * Returns shard id where failure occurred
-     *
-     * @return shard id
-     */
-    @Override
-    public int shardId() {
-        return this.shardId.id();
-    }
-
-    /**
-     * Returns reason for the failure
-     *
-     * @return reason for the failure
-     */
-    @Override
-    public String reason() {
-        return this.reason;
-    }
-
-    /**
-     * Returns {@link RestStatus} corresponding to this failure
-     *
-     * @return REST status
-     */
-    @Override
-    public RestStatus status() {
-        return status;
-    }
-
-    @Override
-    public Throwable getCause() {
-        return new IndexShardSnapshotFailedException(shardId, reason);
     }
 
     /**
@@ -142,7 +91,7 @@ public class SnapshotShardFailure implements ShardOperationFailedException {
      * @param in stream input
      * @return shard failure information
      */
-    public static SnapshotShardFailure readSnapshotShardFailure(StreamInput in) throws IOException {
+    static SnapshotShardFailure readSnapshotShardFailure(StreamInput in) throws IOException {
         SnapshotShardFailure exp = new SnapshotShardFailure();
         exp.readFrom(in);
         return exp;
@@ -152,6 +101,8 @@ public class SnapshotShardFailure implements ShardOperationFailedException {
     public void readFrom(StreamInput in) throws IOException {
         nodeId = in.readOptionalString();
         shardId = ShardId.readShardId(in);
+        super.shardId = shardId.getId();
+        super.index = shardId.getIndexName();
         reason = in.readString();
         status = RestStatus.readFrom(in);
     }

server/src/main/java/org/elasticsearch/transport/TcpTransport.java

@@ -588,7 +588,7 @@ public abstract class TcpTransport extends AbstractLifecycleComponent implements
      * takes a {@link ConnectionProfile} that have been passed as a parameter to the public methods
      * and resolves it to a fully specified (i.e., no nulls) profile
      */
-    static ConnectionProfile resolveConnectionProfile(@Nullable ConnectionProfile connectionProfile,
+    protected static ConnectionProfile resolveConnectionProfile(@Nullable ConnectionProfile connectionProfile,
                                                       ConnectionProfile defaultConnectionProfile) {
         Objects.requireNonNull(defaultConnectionProfile);
         if (connectionProfile == null) {

server/src/test/java/org/elasticsearch/ExceptionsHelperTests.java

@@ -174,36 +174,13 @@ public class ExceptionsHelperTests extends ESTestCase {
         return new ShardSearchFailure(queryShardException, null);
     }
 
-    public void testGroupByNullCause() {
-        ShardOperationFailedException[] failures = new ShardOperationFailedException[] {
-            new ShardSearchFailure("error", createSearchShardTarget("node0", 0, "index", null)),
-            new ShardSearchFailure("error", createSearchShardTarget("node1", 1, "index", null)),
-            new ShardSearchFailure("error", createSearchShardTarget("node1", 1, "index2", null)),
-            new ShardSearchFailure("error", createSearchShardTarget("node2", 2, "index", "cluster1")),
-            new ShardSearchFailure("error", createSearchShardTarget("node1", 1, "index", "cluster1")),
-            new ShardSearchFailure("a different error", createSearchShardTarget("node3", 3, "index", "cluster1"))
-        };
-
-        ShardOperationFailedException[] groupBy = ExceptionsHelper.groupBy(failures);
-        assertThat(groupBy.length, equalTo(4));
-        String[] expectedIndices = new String[]{"index", "index2", "cluster1:index", "cluster1:index"};
-        String[] expectedErrors = new String[]{"error", "error", "error", "a different error"};
-
-        int i = 0;
-        for (ShardOperationFailedException shardOperationFailedException : groupBy) {
-            assertThat(shardOperationFailedException.reason(), equalTo(expectedErrors[i]));
-            assertThat(shardOperationFailedException.index(), equalTo(expectedIndices[i++]));
-        }
-    }
-
     public void testGroupByNullIndex() {
         ShardOperationFailedException[] failures = new ShardOperationFailedException[] {
-            new ShardSearchFailure("error", null),
             new ShardSearchFailure(new IllegalArgumentException("error")),
             new ShardSearchFailure(new ParsingException(0, 0, "error", null)),
         };
 
         ShardOperationFailedException[] groupBy = ExceptionsHelper.groupBy(failures);
-        assertThat(groupBy.length, equalTo(3));
+        assertThat(groupBy.length, equalTo(2));
     }
 }

server/src/test/java/org/elasticsearch/action/ShardOperationFailedExceptionTests.java

@@ -0,0 +1,76 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.action;
+
+import org.elasticsearch.common.Nullable;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.rest.RestStatus;
+import org.elasticsearch.test.ESTestCase;
+
+import java.io.IOException;
+
+public class ShardOperationFailedExceptionTests extends ESTestCase {
+
+    public void testCauseCannotBeNull() {
+        NullPointerException nullPointerException = expectThrows(NullPointerException.class, () -> new Failure(
+            randomAlphaOfLengthBetween(3, 10), randomInt(), randomAlphaOfLengthBetween(5, 10), randomFrom(RestStatus.values()), null));
+        assertEquals("cause cannot be null", nullPointerException.getMessage());
+    }
+
+    public void testStatusCannotBeNull() {
+        NullPointerException nullPointerException = expectThrows(NullPointerException.class, () -> new Failure(
+            randomAlphaOfLengthBetween(3, 10), randomInt(), randomAlphaOfLengthBetween(5, 10), null, new IllegalArgumentException()));
+        assertEquals("status cannot be null", nullPointerException.getMessage());
+    }
+
+    public void testReasonCannotBeNull() {
+        NullPointerException nullPointerException = expectThrows(NullPointerException.class, () -> new Failure(
+            randomAlphaOfLengthBetween(3, 10), randomInt(), null, randomFrom(RestStatus.values()), new IllegalArgumentException()));
+        assertEquals("reason cannot be null", nullPointerException.getMessage());
+    }
+
+    public void testIndexIsNullable() {
+        new Failure(null, randomInt(), randomAlphaOfLengthBetween(5, 10), randomFrom(RestStatus.values()), new IllegalArgumentException());
+    }
+
+    private static class Failure extends ShardOperationFailedException {
+
+        Failure(@Nullable String index, int shardId, String reason, RestStatus status, Throwable cause) {
+           super(index, shardId, reason, status, cause);
+        }
+
+        @Override
+        public void readFrom(StreamInput in) throws IOException {
+
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+
+        }
+
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            return null;
+        }
+    }
+}

server/src/test/java/org/elasticsearch/index/query/QueryShardContextTests.java

@@ -22,8 +22,10 @@ import org.apache.lucene.search.MatchNoDocsQuery;
 import org.apache.lucene.search.Query;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
+import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.lucene.search.Queries;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.fielddata.IndexFieldData;
 import org.elasticsearch.index.fielddata.plain.AbstractAtomicOrdinalsFieldData;
@@ -37,6 +39,7 @@ import org.elasticsearch.test.ESTestCase;
 import org.hamcrest.Matchers;
 
 import java.io.IOException;
+import java.util.Collections;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
@@ -49,24 +52,7 @@ import static org.mockito.Mockito.when;
 public class QueryShardContextTests extends ESTestCase {
 
     public void testFailIfFieldMappingNotFound() {
-        IndexMetaData.Builder indexMetadataBuilder = new IndexMetaData.Builder("index");
-        indexMetadataBuilder.settings(Settings.builder().put("index.version.created", Version.CURRENT)
-            .put("index.number_of_shards", 1)
-            .put("index.number_of_replicas", 1)
-        );
-        IndexMetaData indexMetaData = indexMetadataBuilder.build();
-        IndexSettings indexSettings = new IndexSettings(indexMetaData, Settings.EMPTY);
-        MapperService mapperService = mock(MapperService.class);
-        when(mapperService.getIndexSettings()).thenReturn(indexSettings);
-        when(mapperService.index()).thenReturn(indexMetaData.getIndex());
-        final long nowInMillis = randomNonNegativeLong();
-
-        QueryShardContext context = new QueryShardContext(
-            0, indexSettings, null, (mappedFieldType, idxName) ->
-                mappedFieldType.fielddataBuilder(idxName).build(indexSettings, mappedFieldType, null, null, null)
-                , mapperService, null, null, xContentRegistry(), writableRegistry(), null, null,
-            () -> nowInMillis, null);
-
+        QueryShardContext context = createQueryShardContext(IndexMetaData.INDEX_UUID_NA_VALUE, null);
         context.setAllowUnmappedFields(false);
         MappedFieldType fieldType = new TextFieldMapper.TextFieldType();
         MappedFieldType result = context.failIfFieldMappingNotFound("name", fieldType);
@@ -91,30 +77,16 @@ public class QueryShardContextTests extends ESTestCase {
     }
 
     public void testClusterAlias() throws IOException {
-        IndexMetaData.Builder indexMetadataBuilder = new IndexMetaData.Builder("index");
-        indexMetadataBuilder.settings(Settings.builder().put("index.version.created", Version.CURRENT)
-            .put("index.number_of_shards", 1)
-            .put("index.number_of_replicas", 1)
-        );
-        IndexMetaData indexMetaData = indexMetadataBuilder.build();
-        IndexSettings indexSettings = new IndexSettings(indexMetaData, Settings.EMPTY);
-        MapperService mapperService = mock(MapperService.class);
-        when(mapperService.getIndexSettings()).thenReturn(indexSettings);
-        when(mapperService.index()).thenReturn(indexMetaData.getIndex());
-        final long nowInMillis = randomNonNegativeLong();
-
-        Mapper.BuilderContext ctx = new Mapper.BuilderContext(indexSettings.getSettings(), new ContentPath());
-        IndexFieldMapper mapper = new IndexFieldMapper.Builder(null).build(ctx);
         final String clusterAlias = randomBoolean() ? null : "remote_cluster";
-        QueryShardContext context = new QueryShardContext(
-            0, indexSettings, null, (mappedFieldType, indexname) ->
-            mappedFieldType.fielddataBuilder(indexname).build(indexSettings, mappedFieldType, null, null, mapperService)
-            , mapperService, null, null, xContentRegistry(), writableRegistry(), null, null,
-            () -> nowInMillis, clusterAlias);
+        QueryShardContext context = createQueryShardContext(IndexMetaData.INDEX_UUID_NA_VALUE, clusterAlias);
+
+
+        Mapper.BuilderContext ctx = new Mapper.BuilderContext(context.getIndexSettings().getSettings(), new ContentPath());
+        IndexFieldMapper mapper = new IndexFieldMapper.Builder(null).build(ctx);
 
         IndexFieldData<?> forField = context.getForField(mapper.fieldType());
-        String expected = clusterAlias == null ? indexMetaData.getIndex().getName()
-            : clusterAlias + ":" + indexMetaData.getIndex().getName();
+        String expected = clusterAlias == null ? context.getIndexSettings().getIndexMetaData().getIndex().getName()
+            : clusterAlias + ":" + context.getIndexSettings().getIndex().getName();
         assertEquals(expected, ((AbstractAtomicOrdinalsFieldData)forField.load(null)).getOrdinalsValues().lookupOrd(0).utf8ToString());
         Query query = mapper.fieldType().termQuery("index", context);
         if (clusterAlias == null) {
@@ -133,4 +105,32 @@ public class QueryShardContextTests extends ESTestCase {
         assertThat(query, Matchers.instanceOf(MatchNoDocsQuery.class));
     }
 
+    public void testGetFullyQualifiedIndex() {
+        String clusterAlias = randomAlphaOfLengthBetween(5, 10);
+        String indexUuid = randomAlphaOfLengthBetween(3, 10);
+        QueryShardContext shardContext = createQueryShardContext(indexUuid, clusterAlias);
+        assertThat(shardContext.getFullyQualifiedIndex().getName(), equalTo(clusterAlias + ":index"));
+        assertThat(shardContext.getFullyQualifiedIndex().getUUID(), equalTo(indexUuid));
+    }
+
+    public static QueryShardContext createQueryShardContext(String indexUuid, String clusterAlias) {
+        IndexMetaData.Builder indexMetadataBuilder = new IndexMetaData.Builder("index");
+        indexMetadataBuilder.settings(Settings.builder().put("index.version.created", Version.CURRENT)
+            .put("index.number_of_shards", 1)
+            .put("index.number_of_replicas", 1)
+            .put(IndexMetaData.SETTING_INDEX_UUID, indexUuid)
+        );
+        IndexMetaData indexMetaData = indexMetadataBuilder.build();
+        IndexSettings indexSettings = new IndexSettings(indexMetaData, Settings.EMPTY);
+        MapperService mapperService = mock(MapperService.class);
+        when(mapperService.getIndexSettings()).thenReturn(indexSettings);
+        when(mapperService.index()).thenReturn(indexMetaData.getIndex());
+        final long nowInMillis = randomNonNegativeLong();
+
+        return new QueryShardContext(
+            0, indexSettings, null, (mappedFieldType, idxName) ->
+            mappedFieldType.fielddataBuilder(idxName).build(indexSettings, mappedFieldType, null, null, null)
+            , mapperService, null, null, NamedXContentRegistry.EMPTY, new NamedWriteableRegistry(Collections.emptyList()), null, null,
+            () -> nowInMillis, clusterAlias);
+    }
 }

server/src/test/java/org/elasticsearch/index/query/QueryShardExceptionTests.java

@@ -0,0 +1,53 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.index.query;
+
+import org.elasticsearch.index.Index;
+import org.elasticsearch.test.ESTestCase;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+
+public class QueryShardExceptionTests extends ESTestCase {
+
+    public void testCreateFromQueryShardContext() {
+        String indexUuid = randomAlphaOfLengthBetween(5, 10);
+        String clusterAlias = randomAlphaOfLengthBetween(5, 10);
+        QueryShardContext queryShardContext = QueryShardContextTests.createQueryShardContext(indexUuid, clusterAlias);
+        {
+            QueryShardException queryShardException = new QueryShardException(queryShardContext, "error");
+            assertThat(queryShardException.getIndex().getName(), equalTo(clusterAlias + ":index"));
+            assertThat(queryShardException.getIndex().getUUID(), equalTo(indexUuid));
+        }
+        {
+            QueryShardException queryShardException = new QueryShardException(queryShardContext, "error", new IllegalArgumentException());
+            assertThat(queryShardException.getIndex().getName(), equalTo(clusterAlias + ":index"));
+            assertThat(queryShardException.getIndex().getUUID(), equalTo(indexUuid));
+        }
+    }
+
+    public void testCreateFromIndex() {
+        String indexUuid = randomAlphaOfLengthBetween(5, 10);
+        String indexName = randomAlphaOfLengthBetween(5, 10);
+        Index index = new Index(indexName, indexUuid);
+        QueryShardException queryShardException = new QueryShardException(index, "error", new IllegalArgumentException());
+        assertThat(queryShardException.getIndex().getName(), equalTo(indexName));
+        assertThat(queryShardException.getIndex().getUUID(), equalTo(indexUuid));
+    }
+}

server/src/test/java/org/elasticsearch/index/query/WildcardQueryBuilderTests.java

@@ -32,7 +32,6 @@ import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
-import static org.elasticsearch.test.AbstractBuilderTestCase.STRING_ALIAS_FIELD_NAME;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 
@@ -143,7 +142,7 @@ public class WildcardQueryBuilderTests extends AbstractQueryTestCase<WildcardQue
 
     public void testIndexWildcard() throws IOException {
         QueryShardContext context = createShardContext();
-        String index = context.getFullyQualifiedIndexName();
+        String index = context.getFullyQualifiedIndex().getName();
 
         Query query = new WildcardQueryBuilder("_index", index).doToQuery(context);
         assertThat(query instanceof MatchAllDocsQuery, equalTo(true));

server/src/test/java/org/elasticsearch/index/seqno/ReplicationTrackerTests.java

@@ -47,7 +47,9 @@ import java.util.Set;
 import java.util.concurrent.BrokenBarrierException;
 import java.util.concurrent.CyclicBarrier;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.Function;
+import java.util.function.LongConsumer;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -60,7 +62,7 @@ import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.not;
 
 public class ReplicationTrackerTests extends ESTestCase {
-
+    
     public void testEmptyShards() {
         final ReplicationTracker tracker = newTracker(AllocationId.newInitializing());
         assertThat(tracker.getGlobalCheckpoint(), equalTo(UNASSIGNED_SEQ_NO));
@@ -99,6 +101,11 @@ public class ReplicationTrackerTests extends ESTestCase {
         return allocationIds.stream().map(AllocationId::getId).collect(Collectors.toSet());
     }
 
+    private void updateLocalCheckpoint(final ReplicationTracker tracker, final String allocationId, final long localCheckpoint) {
+        tracker.updateLocalCheckpoint(allocationId, localCheckpoint);
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(tracker.getGlobalCheckpoint()));
+    }
+    
     public void testGlobalCheckpointUpdate() {
         final long initialClusterStateVersion = randomNonNegativeLong();
         Map<AllocationId, Long> allocations = new HashMap<>();
@@ -137,14 +144,14 @@ public class ReplicationTrackerTests extends ESTestCase {
         assertThat(tracker.getReplicationGroup().getReplicationTargets().size(), equalTo(1));
         initializing.forEach(aId -> markAsTrackingAndInSyncQuietly(tracker, aId.getId(), NO_OPS_PERFORMED));
         assertThat(tracker.getReplicationGroup().getReplicationTargets().size(), equalTo(1 + initializing.size()));
-        allocations.keySet().forEach(aId -> tracker.updateLocalCheckpoint(aId.getId(), allocations.get(aId)));
+        allocations.keySet().forEach(aId -> updateLocalCheckpoint(tracker, aId.getId(), allocations.get(aId)));
 
         assertThat(tracker.getGlobalCheckpoint(), equalTo(minLocalCheckpoint));
 
         // increment checkpoints
         active.forEach(aId -> allocations.put(aId, allocations.get(aId) + 1 + randomInt(4)));
         initializing.forEach(aId -> allocations.put(aId, allocations.get(aId) + 1 + randomInt(4)));
-        allocations.keySet().forEach(aId -> tracker.updateLocalCheckpoint(aId.getId(), allocations.get(aId)));
+        allocations.keySet().forEach(aId -> updateLocalCheckpoint(tracker, aId.getId(), allocations.get(aId)));
 
         final long minLocalCheckpointAfterUpdates =
                 allocations.entrySet().stream().map(Map.Entry::getValue).min(Long::compareTo).orElse(UNASSIGNED_SEQ_NO);
@@ -153,7 +160,7 @@ public class ReplicationTrackerTests extends ESTestCase {
         final AllocationId extraId = AllocationId.newInitializing();
 
         // first check that adding it without the master blessing doesn't change anything.
-        tracker.updateLocalCheckpoint(extraId.getId(), minLocalCheckpointAfterUpdates + 1 + randomInt(4));
+        updateLocalCheckpoint(tracker, extraId.getId(), minLocalCheckpointAfterUpdates + 1 + randomInt(4));
         assertNull(tracker.checkpoints.get(extraId));
         expectThrows(IllegalStateException.class, () -> tracker.initiateTracking(extraId.getId()));
 
@@ -165,7 +172,7 @@ public class ReplicationTrackerTests extends ESTestCase {
 
         // now notify for the new id
         if (randomBoolean()) {
-            tracker.updateLocalCheckpoint(extraId.getId(), minLocalCheckpointAfterUpdates + 1 + randomInt(4));
+            updateLocalCheckpoint(tracker, extraId.getId(), minLocalCheckpointAfterUpdates + 1 + randomInt(4));
             markAsTrackingAndInSyncQuietly(tracker, extraId.getId(), randomInt((int) minLocalCheckpointAfterUpdates));
         } else {
             markAsTrackingAndInSyncQuietly(tracker, extraId.getId(), minLocalCheckpointAfterUpdates + 1 + randomInt(4));
@@ -175,6 +182,64 @@ public class ReplicationTrackerTests extends ESTestCase {
         assertThat(tracker.getGlobalCheckpoint(), greaterThan(minLocalCheckpoint));
     }
 
+    public void testUpdateGlobalCheckpointOnReplica() {
+        final AllocationId active = AllocationId.newInitializing();
+        final ReplicationTracker tracker = newTracker(active);
+        final long globalCheckpoint = randomLongBetween(NO_OPS_PERFORMED, Long.MAX_VALUE - 1);
+        tracker.updateGlobalCheckpointOnReplica(globalCheckpoint, "test");
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(globalCheckpoint));
+        final long nonUpdate = randomLongBetween(NO_OPS_PERFORMED, globalCheckpoint);
+        updatedGlobalCheckpoint.set(UNASSIGNED_SEQ_NO);
+        tracker.updateGlobalCheckpointOnReplica(nonUpdate, "test");
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(UNASSIGNED_SEQ_NO));
+        final long update = randomLongBetween(globalCheckpoint, Long.MAX_VALUE);
+        tracker.updateGlobalCheckpointOnReplica(update, "test");
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(update));
+    }
+
+    public void testMarkAllocationIdAsInSync() throws BrokenBarrierException, InterruptedException {
+        final long initialClusterStateVersion = randomNonNegativeLong();
+        Map<AllocationId, Long> activeWithCheckpoints = randomAllocationsWithLocalCheckpoints(1, 1);
+        Set<AllocationId> active = new HashSet<>(activeWithCheckpoints.keySet());
+        Map<AllocationId, Long> initializingWithCheckpoints = randomAllocationsWithLocalCheckpoints(1, 1);
+        Set<AllocationId> initializing = new HashSet<>(initializingWithCheckpoints.keySet());
+        final AllocationId primaryId = active.iterator().next();
+        final AllocationId replicaId = initializing.iterator().next();
+        final ReplicationTracker tracker = newTracker(primaryId);
+        tracker.updateFromMaster(initialClusterStateVersion, ids(active), routingTable(initializing, primaryId), emptySet());
+        final long localCheckpoint = randomLongBetween(0, Long.MAX_VALUE - 1);
+        tracker.activatePrimaryMode(localCheckpoint);
+        tracker.initiateTracking(replicaId.getId());
+        final CyclicBarrier barrier = new CyclicBarrier(2);
+        final Thread thread = new Thread(() -> {
+            try {
+                barrier.await();
+                tracker.markAllocationIdAsInSync(
+                        replicaId.getId(),
+                        randomLongBetween(NO_OPS_PERFORMED, localCheckpoint - 1));
+                barrier.await();
+            } catch (BrokenBarrierException | InterruptedException e) {
+                throw new AssertionError(e);
+            }
+        });
+        thread.start();
+        barrier.await();
+        awaitBusy(tracker::pendingInSync);
+        final long updatedLocalCheckpoint = randomLongBetween(1 + localCheckpoint, Long.MAX_VALUE);
+        // there is a shard copy pending in sync, the global checkpoint can not advance
+        updatedGlobalCheckpoint.set(UNASSIGNED_SEQ_NO);
+        tracker.updateLocalCheckpoint(primaryId.getId(), updatedLocalCheckpoint);
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(UNASSIGNED_SEQ_NO));
+        // we are implicitly marking the pending in sync copy as in sync with the current global checkpoint, no advancement should occur
+        tracker.updateLocalCheckpoint(replicaId.getId(), localCheckpoint);
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(UNASSIGNED_SEQ_NO));
+        barrier.await();
+        thread.join();
+        // now we expect that the global checkpoint would advance
+        tracker.markAllocationIdAsInSync(replicaId.getId(), updatedLocalCheckpoint);
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(updatedLocalCheckpoint));
+    }
+
     public void testMissingActiveIdsPreventAdvance() {
         final Map<AllocationId, Long> active = randomAllocationsWithLocalCheckpoints(2, 5);
         final Map<AllocationId, Long> initializing = randomAllocationsWithLocalCheckpoints(0, 5);
@@ -191,14 +256,16 @@ public class ReplicationTrackerTests extends ESTestCase {
                 .entrySet()
                 .stream()
                 .filter(e -> !e.getKey().equals(missingActiveID))
-                .forEach(e -> tracker.updateLocalCheckpoint(e.getKey().getId(), e.getValue()));
+                .forEach(e -> updateLocalCheckpoint(tracker, e.getKey().getId(), e.getValue()));
 
         if (missingActiveID.equals(primaryId) == false) {
             assertThat(tracker.getGlobalCheckpoint(), equalTo(UNASSIGNED_SEQ_NO));
+            assertThat(updatedGlobalCheckpoint.get(), equalTo(UNASSIGNED_SEQ_NO));
         }
         // now update all knowledge of all shards
-        assigned.forEach((aid, localCP) -> tracker.updateLocalCheckpoint(aid.getId(), localCP));
+        assigned.forEach((aid, localCP) -> updateLocalCheckpoint(tracker, aid.getId(), localCP));
         assertThat(tracker.getGlobalCheckpoint(), not(equalTo(UNASSIGNED_SEQ_NO)));
+        assertThat(updatedGlobalCheckpoint.get(), not(equalTo(UNASSIGNED_SEQ_NO)));
     }
 
     public void testMissingInSyncIdsPreventAdvance() {
@@ -213,13 +280,15 @@ public class ReplicationTrackerTests extends ESTestCase {
         randomSubsetOf(randomIntBetween(1, initializing.size() - 1),
             initializing.keySet()).forEach(aId -> markAsTrackingAndInSyncQuietly(tracker, aId.getId(), NO_OPS_PERFORMED));
 
-        active.forEach((aid, localCP) -> tracker.updateLocalCheckpoint(aid.getId(), localCP));
+        active.forEach((aid, localCP) -> updateLocalCheckpoint(tracker, aid.getId(), localCP));
 
         assertThat(tracker.getGlobalCheckpoint(), equalTo(NO_OPS_PERFORMED));
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(NO_OPS_PERFORMED));
 
         // update again
-        initializing.forEach((aid, localCP) -> tracker.updateLocalCheckpoint(aid.getId(), localCP));
+        initializing.forEach((aid, localCP) -> updateLocalCheckpoint(tracker, aid.getId(), localCP));
         assertThat(tracker.getGlobalCheckpoint(), not(equalTo(UNASSIGNED_SEQ_NO)));
+        assertThat(updatedGlobalCheckpoint.get(), not(equalTo(UNASSIGNED_SEQ_NO)));
     }
 
     public void testInSyncIdsAreIgnoredIfNotValidatedByMaster() {
@@ -236,7 +305,7 @@ public class ReplicationTrackerTests extends ESTestCase {
 
         List<Map<AllocationId, Long>> allocations = Arrays.asList(active, initializing, nonApproved);
         Collections.shuffle(allocations, random());
-        allocations.forEach(a -> a.forEach((aid, localCP) -> tracker.updateLocalCheckpoint(aid.getId(), localCP)));
+        allocations.forEach(a -> a.forEach((aid, localCP) -> updateLocalCheckpoint(tracker, aid.getId(), localCP)));
 
         assertThat(tracker.getGlobalCheckpoint(), not(equalTo(UNASSIGNED_SEQ_NO)));
     }
@@ -271,7 +340,7 @@ public class ReplicationTrackerTests extends ESTestCase {
             initializing.forEach(k -> markAsTrackingAndInSyncQuietly(tracker, k.getId(), NO_OPS_PERFORMED));
         }
         if (randomBoolean()) {
-            allocations.forEach((aid, localCP) -> tracker.updateLocalCheckpoint(aid.getId(), localCP));
+            allocations.forEach((aid, localCP) -> updateLocalCheckpoint(tracker, aid.getId(), localCP));
         }
 
         // now remove shards
@@ -281,9 +350,9 @@ public class ReplicationTrackerTests extends ESTestCase {
                     ids(activeToStay.keySet()),
                     routingTable(initializingToStay.keySet(), primaryId),
                     emptySet());
-            allocations.forEach((aid, ckp) -> tracker.updateLocalCheckpoint(aid.getId(), ckp + 10L));
+            allocations.forEach((aid, ckp) -> updateLocalCheckpoint(tracker, aid.getId(), ckp + 10L));
         } else {
-            allocations.forEach((aid, ckp) -> tracker.updateLocalCheckpoint(aid.getId(), ckp + 10L));
+            allocations.forEach((aid, ckp) -> updateLocalCheckpoint(tracker, aid.getId(), ckp + 10L));
             tracker.updateFromMaster(
                     initialClusterStateVersion + 2,
                     ids(activeToStay.keySet()),
@@ -331,7 +400,7 @@ public class ReplicationTrackerTests extends ESTestCase {
         final List<Integer> elements = IntStream.rangeClosed(0, globalCheckpoint - 1).boxed().collect(Collectors.toList());
         Randomness.shuffle(elements);
         for (int i = 0; i < elements.size(); i++) {
-            tracker.updateLocalCheckpoint(trackingAllocationId.getId(), elements.get(i));
+            updateLocalCheckpoint(tracker, trackingAllocationId.getId(), elements.get(i));
             assertFalse(complete.get());
             assertFalse(tracker.getTrackedLocalCheckpointForShard(trackingAllocationId.getId()).inSync);
             assertBusy(() -> assertTrue(tracker.pendingInSync.contains(trackingAllocationId.getId())));
@@ -339,7 +408,7 @@ public class ReplicationTrackerTests extends ESTestCase {
 
         if (randomBoolean()) {
             // normal path, shard catches up
-            tracker.updateLocalCheckpoint(trackingAllocationId.getId(), randomIntBetween(globalCheckpoint, 64));
+            updateLocalCheckpoint(tracker, trackingAllocationId.getId(), randomIntBetween(globalCheckpoint, 64));
             // synchronize with the waiting thread to mark that it is complete
             barrier.await();
             assertTrue(complete.get());
@@ -355,13 +424,16 @@ public class ReplicationTrackerTests extends ESTestCase {
         assertFalse(tracker.pendingInSync.contains(trackingAllocationId.getId()));
         thread.join();
     }
+    
+    private AtomicLong updatedGlobalCheckpoint = new AtomicLong(UNASSIGNED_SEQ_NO);
 
     private ReplicationTracker newTracker(final AllocationId allocationId) {
         return new ReplicationTracker(
                 new ShardId("test", "_na_", 0),
                 allocationId.getId(),
                 IndexSettingsModule.newIndexSettings("test", Settings.EMPTY),
-                UNASSIGNED_SEQ_NO);
+                UNASSIGNED_SEQ_NO,
+                updatedGlobalCheckpoint::set);
     }
 
     public void testWaitForAllocationIdToBeInSyncCanBeInterrupted() throws BrokenBarrierException, InterruptedException {
@@ -488,10 +560,10 @@ public class ReplicationTrackerTests extends ESTestCase {
         // the tracking allocation IDs should play no role in determining the global checkpoint
         final Map<AllocationId, Integer> activeLocalCheckpoints =
                 newActiveAllocationIds.stream().collect(Collectors.toMap(Function.identity(), a -> randomIntBetween(1, 1024)));
-        activeLocalCheckpoints.forEach((a, l) -> tracker.updateLocalCheckpoint(a.getId(), l));
+        activeLocalCheckpoints.forEach((a, l) -> updateLocalCheckpoint(tracker, a.getId(), l));
         final Map<AllocationId, Integer> initializingLocalCheckpoints =
                 newInitializingAllocationIds.stream().collect(Collectors.toMap(Function.identity(), a -> randomIntBetween(1, 1024)));
-        initializingLocalCheckpoints.forEach((a, l) -> tracker.updateLocalCheckpoint(a.getId(), l));
+        initializingLocalCheckpoints.forEach((a, l) -> updateLocalCheckpoint(tracker, a.getId(), l));
         assertTrue(
                 activeLocalCheckpoints
                         .entrySet()
@@ -504,6 +576,7 @@ public class ReplicationTrackerTests extends ESTestCase {
                         .allMatch(e -> tracker.getTrackedLocalCheckpointForShard(e.getKey().getId()).getLocalCheckpoint() == e.getValue()));
         final long minimumActiveLocalCheckpoint = (long) activeLocalCheckpoints.values().stream().min(Integer::compareTo).get();
         assertThat(tracker.getGlobalCheckpoint(), equalTo(minimumActiveLocalCheckpoint));
+        assertThat(updatedGlobalCheckpoint.get(), equalTo(minimumActiveLocalCheckpoint));
         final long minimumInitailizingLocalCheckpoint = (long) initializingLocalCheckpoints.values().stream().min(Integer::compareTo).get();
 
         // now we are going to add a new allocation ID and bring it in sync which should move it to the in-sync allocation IDs
@@ -635,10 +708,11 @@ public class ReplicationTrackerTests extends ESTestCase {
 
         FakeClusterState clusterState = initialState();
         final AllocationId primaryAllocationId = clusterState.routingTable.primaryShard().allocationId();
+        final LongConsumer onUpdate = updatedGlobalCheckpoint -> {};
         ReplicationTracker oldPrimary =
-                new ReplicationTracker(shardId, primaryAllocationId.getId(), indexSettings, UNASSIGNED_SEQ_NO);
+                new ReplicationTracker(shardId, primaryAllocationId.getId(), indexSettings, UNASSIGNED_SEQ_NO, onUpdate);
         ReplicationTracker newPrimary =
-                new ReplicationTracker(shardId, primaryAllocationId.getRelocationId(), indexSettings, UNASSIGNED_SEQ_NO);
+                new ReplicationTracker(shardId, primaryAllocationId.getRelocationId(), indexSettings, UNASSIGNED_SEQ_NO, onUpdate);
 
         Set<String> allocationIds = new HashSet<>(Arrays.asList(oldPrimary.shardAllocationId, newPrimary.shardAllocationId));
 

server/src/test/java/org/elasticsearch/index/shard/IndexShardTests.java

@@ -31,6 +31,7 @@ import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FilterDirectory;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.Constants;
+import org.elasticsearch.Assertions;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.admin.indices.flush.FlushRequest;
@@ -560,28 +561,20 @@ public class IndexShardTests extends IndexShardTestCase {
             ShardRouting primaryRouting = newShardRouting(replicaRouting.shardId(), replicaRouting.currentNodeId(), null,
                 true, ShardRoutingState.STARTED, replicaRouting.allocationId());
             final long newPrimaryTerm = indexShard.getPendingPrimaryTerm() + between(1, 1000);
+            CountDownLatch latch = new CountDownLatch(1);
             indexShard.updateShardState(primaryRouting, newPrimaryTerm, (shard, listener) -> {
                     assertThat(TestTranslog.getCurrentTerm(getTranslog(indexShard)), equalTo(newPrimaryTerm));
+                    latch.countDown();
                 }, 0L,
                 Collections.singleton(indexShard.routingEntry().allocationId().getId()),
                 new IndexShardRoutingTable.Builder(indexShard.shardId()).addShard(primaryRouting).build(),
                 Collections.emptySet());
+            latch.await();
         } else {
             indexShard = newStartedShard(true);
         }
         final long primaryTerm = indexShard.getPendingPrimaryTerm();
         assertEquals(0, indexShard.getActiveOperationsCount());
-        if (indexShard.routingEntry().isRelocationTarget() == false) {
-            try {
-                final PlainActionFuture<Releasable> permitAcquiredFuture = new PlainActionFuture<>();
-                indexShard.acquireReplicaOperationPermit(primaryTerm, indexShard.getGlobalCheckpoint(), permitAcquiredFuture,
-                    ThreadPool.Names.WRITE, "");
-                permitAcquiredFuture.actionGet();
-                fail("shard shouldn't accept operations as replica");
-            } catch (IllegalStateException ignored) {
-
-            }
-        }
         Releasable operation1 = acquirePrimaryOperationPermitBlockingly(indexShard);
         assertEquals(1, indexShard.getActiveOperationsCount());
         Releasable operation2 = acquirePrimaryOperationPermitBlockingly(indexShard);
@@ -590,6 +583,22 @@ public class IndexShardTests extends IndexShardTestCase {
         Releasables.close(operation1, operation2);
         assertEquals(0, indexShard.getActiveOperationsCount());
 
+        if (Assertions.ENABLED && indexShard.routingEntry().isRelocationTarget() == false) {
+            assertThat(expectThrows(AssertionError.class, () -> indexShard.acquireReplicaOperationPermit(primaryTerm,
+                indexShard.getGlobalCheckpoint(), new ActionListener<Releasable>() {
+                    @Override
+                    public void onResponse(Releasable releasable) {
+                        fail();
+                    }
+
+                    @Override
+                    public void onFailure(Exception e) {
+                        fail();
+                    }
+                },
+                ThreadPool.Names.WRITE, "")).getMessage(), containsString("in primary mode cannot be a replication target"));
+        }
+
         closeShards(indexShard);
     }
 
@@ -647,11 +656,11 @@ public class IndexShardTests extends IndexShardTestCase {
         logger.info("shard routing to {}", shardRouting);
 
         assertEquals(0, indexShard.getActiveOperationsCount());
-        if (shardRouting.primary() == false) {
-            final IllegalStateException e =
-                    expectThrows(IllegalStateException.class,
+        if (shardRouting.primary() == false && Assertions.ENABLED) {
+            final AssertionError e =
+                    expectThrows(AssertionError.class,
                         () -> indexShard.acquirePrimaryOperationPermit(null, ThreadPool.Names.WRITE, ""));
-            assertThat(e, hasToString(containsString("shard " + shardRouting + " is not a primary")));
+            assertThat(e, hasToString(containsString("acquirePrimaryOperationPermit should only be called on primary shard")));
         }
 
         final long primaryTerm = indexShard.getPendingPrimaryTerm();

server/src/test/java/org/elasticsearch/rest/action/RestActionsTests.java

@@ -202,49 +202,6 @@ public class RestActionsTests extends ESTestCase {
             new ShardId(new Index(index, IndexMetaData.INDEX_UUID_NA_VALUE), shardId), clusterAlias, OriginalIndices.NONE);
     }
 
-    public void testBuildBroadcastShardsHeaderNullCause() throws Exception {
-        ShardOperationFailedException[] failures = new ShardOperationFailedException[] {
-            new ShardSearchFailure("error", createSearchShardTarget("node0", 0, "index", null)),
-            new ShardSearchFailure("error", createSearchShardTarget("node1", 1, "index", null)),
-            new ShardSearchFailure("error", createSearchShardTarget("node2", 2, "index", "cluster1")),
-            new ShardSearchFailure("error", createSearchShardTarget("node1", 1, "index", "cluster1")),
-            new ShardSearchFailure("a different error", createSearchShardTarget("node3", 3, "index", "cluster1"))
-        };
-
-        XContentBuilder builder = JsonXContent.contentBuilder();
-        builder.prettyPrint();
-        builder.startObject();
-        RestActions.buildBroadcastShardsHeader(builder, ToXContent.EMPTY_PARAMS, 12, 3, 0, 9, failures);
-        builder.endObject();
-        //TODO the reason is not printed out, as a follow-up we should probably either print it out when the cause is null,
-        //or even better enforce that the cause can't be null
-        assertThat(Strings.toString(builder), equalTo("{\n" +
-            "  \"_shards\" : {\n" +
-            "    \"total\" : 12,\n" +
-            "    \"successful\" : 3,\n" +
-            "    \"skipped\" : 0,\n" +
-            "    \"failed\" : 9,\n" +
-            "    \"failures\" : [\n" +
-            "      {\n" +
-            "        \"shard\" : 0,\n" +
-            "        \"index\" : \"index\",\n" +
-            "        \"node\" : \"node0\"\n" +
-            "      },\n" +
-            "      {\n" +
-            "        \"shard\" : 2,\n" +
-            "        \"index\" : \"cluster1:index\",\n" +
-            "        \"node\" : \"node2\"\n" +
-            "      },\n" +
-            "      {\n" +
-            "        \"shard\" : 3,\n" +
-            "        \"index\" : \"cluster1:index\",\n" +
-            "        \"node\" : \"node3\"\n" +
-            "      }\n" +
-            "    ]\n" +
-            "  }\n" +
-            "}"));
-    }
-
     @Override
     protected NamedXContentRegistry xContentRegistry() {
         return xContentRegistry;

server/src/test/java/org/elasticsearch/search/SearchModuleTests.java

@@ -18,6 +18,8 @@
  */
 package org.elasticsearch.search;
 
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.util.CharsRefBuilder;
 import org.elasticsearch.common.inject.ModuleTestCase;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
@@ -64,8 +66,11 @@ import org.elasticsearch.search.internal.SearchContext;
 import org.elasticsearch.search.rescore.QueryRescorerBuilder;
 import org.elasticsearch.search.rescore.RescoreContext;
 import org.elasticsearch.search.rescore.RescorerBuilder;
-import org.elasticsearch.search.suggest.CustomSuggesterSearchIT.CustomSuggestionBuilder;
+import org.elasticsearch.search.suggest.Suggest.Suggestion;
+import org.elasticsearch.search.suggest.Suggester;
 import org.elasticsearch.search.suggest.SuggestionBuilder;
+import org.elasticsearch.search.suggest.SuggestionSearchContext;
+import org.elasticsearch.search.suggest.term.TermSuggestion;
 import org.elasticsearch.search.suggest.term.TermSuggestionBuilder;
 
 import java.io.IOException;
@@ -98,7 +103,8 @@ public class SearchModuleTests extends ModuleTestCase {
         SearchPlugin registersDupeSuggester = new SearchPlugin() {
             @Override
             public List<SearchPlugin.SuggesterSpec<?>> getSuggesters() {
-                return singletonList(new SuggesterSpec<>("term", TermSuggestionBuilder::new, TermSuggestionBuilder::fromXContent));
+                return singletonList(new SuggesterSpec<>(TermSuggestionBuilder.SUGGESTION_NAME,
+                    TermSuggestionBuilder::new, TermSuggestionBuilder::fromXContent, TermSuggestion::new));
             }
         };
         expectThrows(IllegalArgumentException.class, registryForPlugin(registersDupeSuggester));
@@ -183,9 +189,15 @@ public class SearchModuleTests extends ModuleTestCase {
         SearchModule module = new SearchModule(Settings.EMPTY, false, singletonList(new SearchPlugin() {
             @Override
             public List<SuggesterSpec<?>> getSuggesters() {
-                return singletonList(new SuggesterSpec<>("custom", CustomSuggestionBuilder::new, CustomSuggestionBuilder::fromXContent));
+                return singletonList(
+                    new SuggesterSpec<>(
+                        TestSuggestionBuilder.SUGGESTION_NAME,
+                        TestSuggestionBuilder::new,
+                        TestSuggestionBuilder::fromXContent,
+                        TestSuggestion::new));
             }
         }));
+
         assertEquals(1, module.getNamedXContents().stream()
                 .filter(e -> e.categoryClass.equals(SuggestionBuilder.class) &&
                     e.name.match("term", LoggingDeprecationHandler.INSTANCE)).count());
@@ -197,7 +209,7 @@ public class SearchModuleTests extends ModuleTestCase {
                     e.name.match("completion", LoggingDeprecationHandler.INSTANCE)).count());
         assertEquals(1, module.getNamedXContents().stream()
                 .filter(e -> e.categoryClass.equals(SuggestionBuilder.class) &&
-                    e.name.match("custom", LoggingDeprecationHandler.INSTANCE)).count());
+                    e.name.match("test", LoggingDeprecationHandler.INSTANCE)).count());
 
         assertEquals(1, module.getNamedWriteables().stream()
                 .filter(e -> e.categoryClass.equals(SuggestionBuilder.class) && e.name.equals("term")).count());
@@ -206,7 +218,16 @@ public class SearchModuleTests extends ModuleTestCase {
         assertEquals(1, module.getNamedWriteables().stream()
                 .filter(e -> e.categoryClass.equals(SuggestionBuilder.class) && e.name.equals("completion")).count());
         assertEquals(1, module.getNamedWriteables().stream()
-                .filter(e -> e.categoryClass.equals(SuggestionBuilder.class) && e.name.equals("custom")).count());
+                .filter(e -> e.categoryClass.equals(SuggestionBuilder.class) && e.name.equals("test")).count());
+
+        assertEquals(1, module.getNamedWriteables().stream()
+            .filter(e -> e.categoryClass.equals(Suggestion.class) && e.name.equals("term")).count());
+        assertEquals(1, module.getNamedWriteables().stream()
+            .filter(e -> e.categoryClass.equals(Suggestion.class) && e.name.equals("phrase")).count());
+        assertEquals(1, module.getNamedWriteables().stream()
+            .filter(e -> e.categoryClass.equals(Suggestion.class) && e.name.equals("completion")).count());
+        assertEquals(1, module.getNamedWriteables().stream()
+            .filter(e -> e.categoryClass.equals(Suggestion.class) && e.name.equals("test")).count());
     }
 
     public void testRegisterHighlighter() {
@@ -498,4 +519,77 @@ public class SearchModuleTests extends ModuleTestCase {
             return null;
         }
     }
+
+    private static class TestSuggester extends Suggester<SuggestionSearchContext.SuggestionContext> {
+        @Override
+        protected Suggestion<? extends Suggestion.Entry<? extends Suggestion.Entry.Option>> innerExecute(
+                String name,
+                SuggestionSearchContext.SuggestionContext suggestion,
+                IndexSearcher searcher,
+                CharsRefBuilder spare) throws IOException {
+            return null;
+        }
+    }
+
+    private static class TestSuggestionBuilder extends SuggestionBuilder<TestSuggestionBuilder> {
+
+        public static final String SUGGESTION_NAME = "test";
+
+        TestSuggestionBuilder(StreamInput in) throws IOException {
+            super(in);
+        }
+
+        @Override
+        protected void doWriteTo(StreamOutput out) throws IOException {}
+
+        public static TestSuggestionBuilder fromXContent(XContentParser parser) {
+            return null;
+        }
+
+        @Override
+        protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
+            return null;
+        }
+
+        @Override
+        protected SuggestionSearchContext.SuggestionContext build(QueryShardContext context) throws IOException {
+            return null;
+        }
+
+        @Override
+        protected boolean doEquals(TestSuggestionBuilder other) {
+            return false;
+        }
+
+        @Override
+        protected int doHashCode() {
+            return 0;
+        }
+
+        @Override
+        public String getWriteableName() {
+            return "test";
+        }
+    }
+
+    private static class TestSuggestion extends Suggestion {
+        TestSuggestion(StreamInput in) throws IOException {
+            super(in);
+        }
+
+        @Override
+        protected Entry newEntry() {
+            return null;
+        }
+
+        @Override
+        protected Entry newEntry(StreamInput in) throws IOException {
+            return null;
+        }
+
+        @Override
+        public String getWriteableName() {
+            return "test";
+        }
+    }
 }

server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java

@@ -56,7 +56,7 @@ public class InternalAutoDateHistogramTests extends InternalMultiBucketAggregati
                                                        List<PipelineAggregator> pipelineAggregators,
                                                        Map<String, Object> metaData,
                                                        InternalAggregations aggregations) {
-        
+
         roundingInfos = AutoDateHistogramAggregationBuilder.buildRoundings(null);
         int nbBuckets = randomNumberOfBuckets();
         int targetBuckets = randomIntBetween(1, nbBuckets * 2 + 1);
@@ -137,6 +137,12 @@ public class InternalAutoDateHistogramTests extends InternalMultiBucketAggregati
         assertEquals(expectedCounts, actualCounts);
     }
 
+    @Override
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/32215")
+    public void testReduceRandom() {
+        super.testReduceRandom();
+    }
+    
     @Override
     protected Writeable.Reader<InternalAutoDateHistogram> instanceReader() {
         return InternalAutoDateHistogram::new;

server/src/test/java/org/elasticsearch/search/suggest/CustomSuggester.java

@@ -1,63 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.elasticsearch.search.suggest;
-
-import org.apache.lucene.search.IndexSearcher;
-import org.apache.lucene.util.CharsRefBuilder;
-import org.elasticsearch.common.text.Text;
-import org.elasticsearch.index.query.QueryShardContext;
-
-import java.io.IOException;
-import java.util.Locale;
-import java.util.Map;
-
-public class CustomSuggester extends Suggester<CustomSuggester.CustomSuggestionsContext> {
-
-    public static final CustomSuggester INSTANCE = new CustomSuggester();
-
-    // This is a pretty dumb implementation which returns the original text + fieldName + custom config option + 12 or 123
-    @Override
-    public Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>> innerExecute(String name, CustomSuggestionsContext suggestion, IndexSearcher searcher, CharsRefBuilder spare) throws IOException {
-        // Get the suggestion context
-        String text = suggestion.getText().utf8ToString();
-
-        // create two suggestions with 12 and 123 appended
-        Suggest.Suggestion<Suggest.Suggestion.Entry<Suggest.Suggestion.Entry.Option>> response = new Suggest.Suggestion<>(name, suggestion.getSize());
-
-        String firstSuggestion = String.format(Locale.ROOT, "%s-%s-%s-%s", text, suggestion.getField(), suggestion.options.get("suffix"), "12");
-        Suggest.Suggestion.Entry<Suggest.Suggestion.Entry.Option> resultEntry12 = new Suggest.Suggestion.Entry<>(new Text(firstSuggestion), 0, text.length() + 2);
-        response.addTerm(resultEntry12);
-
-        String secondSuggestion = String.format(Locale.ROOT, "%s-%s-%s-%s", text, suggestion.getField(), suggestion.options.get("suffix"), "123");
-        Suggest.Suggestion.Entry<Suggest.Suggestion.Entry.Option> resultEntry123 = new Suggest.Suggestion.Entry<>(new Text(secondSuggestion), 0, text.length() + 3);
-        response.addTerm(resultEntry123);
-
-        return response;
-    }
-
-    public static class CustomSuggestionsContext extends SuggestionSearchContext.SuggestionContext {
-
-        public Map<String, Object> options;
-
-        public CustomSuggestionsContext(QueryShardContext context, Map<String, Object> options) {
-            super(new CustomSuggester(), context);
-            this.options = options;
-        }
-    }
-}

server/src/test/java/org/elasticsearch/search/suggest/CustomSuggesterSearchIT.java

@@ -1,212 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.elasticsearch.search.suggest;
-
-import org.elasticsearch.action.search.SearchRequestBuilder;
-import org.elasticsearch.action.search.SearchResponse;
-import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParsingException;
-import org.elasticsearch.common.io.stream.StreamInput;
-import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.common.lucene.BytesRefs;
-import org.elasticsearch.common.util.CollectionUtils;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.index.query.QueryShardContext;
-import org.elasticsearch.plugins.Plugin;
-import org.elasticsearch.plugins.SearchPlugin;
-import org.elasticsearch.search.suggest.SuggestionSearchContext.SuggestionContext;
-import org.elasticsearch.test.ESIntegTestCase;
-import org.elasticsearch.test.ESIntegTestCase.ClusterScope;
-import org.elasticsearch.test.ESIntegTestCase.Scope;
-
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
-import java.util.Objects;
-
-import static java.util.Collections.singletonList;
-import static org.elasticsearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
-import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
-import static org.hamcrest.Matchers.hasSize;
-import static org.hamcrest.Matchers.is;
-
-/**
- * Integration test for registering a custom suggester.
- */
-@ClusterScope(scope= Scope.SUITE, numDataNodes =1)
-public class CustomSuggesterSearchIT extends ESIntegTestCase {
-    @Override
-    protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Arrays.asList(CustomSuggesterPlugin.class);
-    }
-
-    @Override
-    protected Collection<Class<? extends Plugin>> transportClientPlugins() {
-        return Arrays.asList(CustomSuggesterPlugin.class);
-    }
-
-    public static class CustomSuggesterPlugin extends Plugin implements SearchPlugin {
-        @Override
-        public List<SuggesterSpec<?>> getSuggesters() {
-            return singletonList(new SuggesterSpec<CustomSuggestionBuilder>("custom", CustomSuggestionBuilder::new,
-                    CustomSuggestionBuilder::fromXContent));
-        }
-    }
-
-    public void testThatCustomSuggestersCanBeRegisteredAndWork() throws Exception {
-        createIndex("test");
-        client().prepareIndex("test", "test", "1").setSource(jsonBuilder()
-                .startObject()
-                .field("name", "arbitrary content")
-                .endObject())
-                .setRefreshPolicy(IMMEDIATE).get();
-
-        String randomText = randomAlphaOfLength(10);
-        String randomField = randomAlphaOfLength(10);
-        String randomSuffix = randomAlphaOfLength(10);
-        SuggestBuilder suggestBuilder = new SuggestBuilder();
-        suggestBuilder.addSuggestion("someName", new CustomSuggestionBuilder(randomField, randomSuffix).text(randomText));
-        SearchRequestBuilder searchRequestBuilder = client().prepareSearch("test").setTypes("test").setFrom(0).setSize(1)
-                .suggest(suggestBuilder);
-
-        SearchResponse searchResponse = searchRequestBuilder.execute().actionGet();
-
-        // TODO: infer type once JI-9019884 is fixed
-        // TODO: see also JDK-8039214
-        List<Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>> suggestions =
-            CollectionUtils.<Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>>iterableAsArrayList(
-                searchResponse.getSuggest().getSuggestion("someName"));
-        assertThat(suggestions, hasSize(2));
-        assertThat(suggestions.get(0).getText().string(),
-            is(String.format(Locale.ROOT, "%s-%s-%s-12", randomText, randomField, randomSuffix)));
-        assertThat(suggestions.get(1).getText().string(),
-            is(String.format(Locale.ROOT, "%s-%s-%s-123", randomText, randomField, randomSuffix)));
-    }
-
-    public static class CustomSuggestionBuilder extends SuggestionBuilder<CustomSuggestionBuilder> {
-        protected static final ParseField RANDOM_SUFFIX_FIELD = new ParseField("suffix");
-
-        private String randomSuffix;
-
-        public CustomSuggestionBuilder(String randomField, String randomSuffix) {
-            super(randomField);
-            this.randomSuffix = randomSuffix;
-        }
-
-        /**
-         * Read from a stream.
-         */
-        public CustomSuggestionBuilder(StreamInput in) throws IOException {
-            super(in);
-            this.randomSuffix = in.readString();
-        }
-
-        @Override
-        public void doWriteTo(StreamOutput out) throws IOException {
-            out.writeString(randomSuffix);
-        }
-
-        @Override
-        protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.field(RANDOM_SUFFIX_FIELD.getPreferredName(), randomSuffix);
-            return builder;
-        }
-
-        @Override
-        public String getWriteableName() {
-            return "custom";
-        }
-
-        @Override
-        protected boolean doEquals(CustomSuggestionBuilder other) {
-            return Objects.equals(randomSuffix, other.randomSuffix);
-        }
-
-        @Override
-        protected int doHashCode() {
-            return Objects.hash(randomSuffix);
-        }
-
-        public static CustomSuggestionBuilder fromXContent(XContentParser parser) throws IOException {
-            XContentParser.Token token;
-            String currentFieldName = null;
-            String fieldname = null;
-            String suffix = null;
-            String analyzer = null;
-            int sizeField = -1;
-            int shardSize = -1;
-            while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
-                if (token == XContentParser.Token.FIELD_NAME) {
-                    currentFieldName = parser.currentName();
-                } else if (token.isValue()) {
-                    if (SuggestionBuilder.ANALYZER_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
-                        analyzer = parser.text();
-                    } else if (SuggestionBuilder.FIELDNAME_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
-                        fieldname = parser.text();
-                    } else if (SuggestionBuilder.SIZE_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
-                        sizeField = parser.intValue();
-                    } else if (SuggestionBuilder.SHARDSIZE_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
-                        shardSize = parser.intValue();
-                    } else if (RANDOM_SUFFIX_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
-                        suffix = parser.text();
-                    }
-                } else {
-                    throw new ParsingException(parser.getTokenLocation(),
-                                               "suggester[custom] doesn't support field [" + currentFieldName + "]");
-                }
-            }
-
-            // now we should have field name, check and copy fields over to the suggestion builder we return
-            if (fieldname == null) {
-                throw new ParsingException(parser.getTokenLocation(), "the required field option is missing");
-            }
-            CustomSuggestionBuilder builder = new CustomSuggestionBuilder(fieldname, suffix);
-            if (analyzer != null) {
-                builder.analyzer(analyzer);
-            }
-            if (sizeField != -1) {
-                builder.size(sizeField);
-            }
-            if (shardSize != -1) {
-                builder.shardSize(shardSize);
-            }
-            return builder;
-        }
-
-        @Override
-        public SuggestionContext build(QueryShardContext context) throws IOException {
-            Map<String, Object> options = new HashMap<>();
-            options.put(FIELDNAME_FIELD.getPreferredName(), field());
-            options.put(RANDOM_SUFFIX_FIELD.getPreferredName(), randomSuffix);
-            CustomSuggester.CustomSuggestionsContext customSuggestionsContext =
-                new CustomSuggester.CustomSuggestionsContext(context, options);
-            customSuggestionsContext.setField(field());
-            assert text != null;
-            customSuggestionsContext.setText(BytesRefs.toBytesRef(text));
-            return customSuggestionsContext;
-        }
-
-    }
-
-}

server/src/test/java/org/elasticsearch/search/suggest/SuggestTests.java

@@ -19,9 +19,14 @@
 
 package org.elasticsearch.search.suggest;
 
+import org.elasticsearch.Version;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.io.stream.BytesStreamOutput;
+import org.elasticsearch.common.io.stream.NamedWriteableAwareStreamInput;
+import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.text.Text;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.ToXContent;
@@ -30,6 +35,7 @@ import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.rest.action.search.RestSearchAction;
+import org.elasticsearch.search.SearchModule;
 import org.elasticsearch.search.suggest.Suggest.Suggestion;
 import org.elasticsearch.search.suggest.Suggest.Suggestion.Entry;
 import org.elasticsearch.search.suggest.Suggest.Suggestion.Entry.Option;
@@ -37,6 +43,7 @@ import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
 import org.elasticsearch.search.suggest.phrase.PhraseSuggestion;
 import org.elasticsearch.search.suggest.term.TermSuggestion;
 import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.test.VersionUtils;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -44,6 +51,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
+import static java.util.Collections.emptyList;
 import static org.elasticsearch.common.xcontent.XContentHelper.toXContent;
 import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
 import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureFieldName;
@@ -114,10 +122,11 @@ public class SuggestTests extends ESTestCase {
     }
 
     public void testToXContent() throws IOException {
-        Option option = new Option(new Text("someText"), new Text("somethingHighlighted"), 1.3f, true);
-        Entry<Option> entry = new Entry<>(new Text("entryText"), 42, 313);
+        PhraseSuggestion.Entry.Option option = new PhraseSuggestion.Entry.Option(new Text("someText"), new Text("somethingHighlighted"),
+            1.3f, true);
+        PhraseSuggestion.Entry entry = new PhraseSuggestion.Entry(new Text("entryText"), 42, 313);
         entry.addOption(option);
-        Suggestion<Entry<Option>> suggestion = new Suggestion<>("suggestionName", 5);
+        PhraseSuggestion suggestion = new PhraseSuggestion("suggestionName", 5);
         suggestion.addTerm(entry);
         Suggest suggest = new Suggest(Collections.singletonList(suggestion));
         BytesReference xContent = toXContent(suggest, XContentType.JSON, randomBoolean());
@@ -196,9 +205,9 @@ public class SuggestTests extends ESTestCase {
         String secondWord = randomAlphaOfLength(10);
         Text suggestionText = new Text(suggestedWord + " " + secondWord);
         Text highlighted = new Text("<em>" + suggestedWord + "</em> " + secondWord);
-        PhraseSuggestion.Entry.Option option1 = new Option(suggestionText, highlighted, 0.7f, false);
-        PhraseSuggestion.Entry.Option option2 = new Option(suggestionText, highlighted, 0.8f, true);
-        PhraseSuggestion.Entry.Option option3 = new Option(suggestionText, highlighted, 0.6f);
+        PhraseSuggestion.Entry.Option option1 = new PhraseSuggestion.Entry.Option(suggestionText, highlighted, 0.7f, false);
+        PhraseSuggestion.Entry.Option option2 = new PhraseSuggestion.Entry.Option(suggestionText, highlighted, 0.8f, true);
+        PhraseSuggestion.Entry.Option option3 = new PhraseSuggestion.Entry.Option(suggestionText, highlighted, 0.6f);
         assertEquals(suggestionText, option1.getText());
         assertEquals(highlighted, option1.getHighlighted());
         assertFalse(option1.collateMatch());
@@ -214,4 +223,39 @@ public class SuggestTests extends ESTestCase {
         assertTrue(option1.getScore() > 0.7f);
         assertTrue(option1.collateMatch());
     }
+
+    public void testSerialization() throws IOException {
+        final Version bwcVersion = VersionUtils.randomVersionBetween(random(),
+            Version.CURRENT.minimumCompatibilityVersion(), Version.CURRENT);
+
+        final Suggest suggest = createTestItem();
+        final Suggest bwcSuggest;
+
+        NamedWriteableRegistry registry = new NamedWriteableRegistry
+            (new SearchModule(Settings.EMPTY, false, emptyList()).getNamedWriteables());
+
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            out.setVersion(bwcVersion);
+            suggest.writeTo(out);
+            try (NamedWriteableAwareStreamInput in = new NamedWriteableAwareStreamInput(out.bytes().streamInput(), registry)) {
+                in.setVersion(bwcVersion);
+                bwcSuggest = new Suggest(in);
+            }
+        }
+
+        assertEquals(suggest, bwcSuggest);
+
+        final Suggest backAgain;
+
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            out.setVersion(Version.CURRENT);
+            bwcSuggest.writeTo(out);
+            try (NamedWriteableAwareStreamInput in = new NamedWriteableAwareStreamInput(out.bytes().streamInput(), registry)) {
+                in.setVersion(Version.CURRENT);
+                backAgain = new Suggest(in);
+            }
+        }
+
+        assertEquals(suggest, backAgain);
+    }
 }

server/src/test/java/org/elasticsearch/search/suggest/SuggestionEntryTests.java

@@ -129,10 +129,12 @@ public class SuggestionEntryTests extends ESTestCase {
     }
 
     public void testToXContent() throws IOException {
-        Option option = new Option(new Text("someText"), new Text("somethingHighlighted"), 1.3f, true);
-        Entry<Option> entry = new Entry<>(new Text("entryText"), 42, 313);
-        entry.addOption(option);
-        BytesReference xContent = toXContent(entry, XContentType.JSON, randomBoolean());
+        PhraseSuggestion.Entry.Option phraseOption = new PhraseSuggestion.Entry.Option(new Text("someText"),
+                new Text("somethingHighlighted"),
+            1.3f, true);
+        PhraseSuggestion.Entry phraseEntry = new PhraseSuggestion.Entry(new Text("entryText"), 42, 313);
+        phraseEntry.addOption(phraseOption);
+        BytesReference xContent = toXContent(phraseEntry, XContentType.JSON, randomBoolean());
         assertEquals(
                 "{\"text\":\"entryText\","
                 + "\"offset\":42,"
@@ -144,11 +146,10 @@ public class SuggestionEntryTests extends ESTestCase {
                     + "\"collate_match\":true}"
                 + "]}", xContent.utf8ToString());
 
-        org.elasticsearch.search.suggest.term.TermSuggestion.Entry.Option termOption =
-                new org.elasticsearch.search.suggest.term.TermSuggestion.Entry.Option(new Text("termSuggestOption"), 42, 3.13f);
-        entry = new Entry<>(new Text("entryText"), 42, 313);
-        entry.addOption(termOption);
-        xContent = toXContent(entry, XContentType.JSON, randomBoolean());
+        TermSuggestion.Entry.Option termOption = new TermSuggestion.Entry.Option(new Text("termSuggestOption"), 42, 3.13f);
+        TermSuggestion.Entry termEntry = new TermSuggestion.Entry(new Text("entryText"), 42, 313);
+        termEntry.addOption(termOption);
+        xContent = toXContent(termEntry, XContentType.JSON, randomBoolean());
         assertEquals(
                 "{\"text\":\"entryText\","
                 + "\"offset\":42,"
@@ -159,12 +160,11 @@ public class SuggestionEntryTests extends ESTestCase {
                     + "\"freq\":42}"
                 + "]}", xContent.utf8ToString());
 
-        org.elasticsearch.search.suggest.completion.CompletionSuggestion.Entry.Option completionOption =
-                new org.elasticsearch.search.suggest.completion.CompletionSuggestion.Entry.Option(-1, new Text("completionOption"),
+        CompletionSuggestion.Entry.Option completionOption = new CompletionSuggestion.Entry.Option(-1, new Text("completionOption"),
                         3.13f, Collections.singletonMap("key", Collections.singleton("value")));
-        entry = new Entry<>(new Text("entryText"), 42, 313);
-        entry.addOption(completionOption);
-        xContent = toXContent(entry, XContentType.JSON, randomBoolean());
+        CompletionSuggestion.Entry completionEntry = new CompletionSuggestion.Entry(new Text("entryText"), 42, 313);
+        completionEntry.addOption(completionOption);
+        xContent = toXContent(completionEntry, XContentType.JSON, randomBoolean());
         assertEquals(
                 "{\"text\":\"entryText\","
                 + "\"offset\":42,"

server/src/test/java/org/elasticsearch/search/suggest/SuggestionOptionTests.java

@@ -25,6 +25,7 @@ import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.search.suggest.Suggest.Suggestion.Entry.Option;
+import org.elasticsearch.search.suggest.phrase.PhraseSuggestion;
 import org.elasticsearch.test.ESTestCase;
 
 import java.io.IOException;
@@ -41,7 +42,7 @@ public class SuggestionOptionTests extends ESTestCase {
         float score = randomFloat();
         Text highlighted = randomFrom((Text) null, new Text(randomAlphaOfLengthBetween(5, 15)));
         Boolean collateMatch = randomFrom((Boolean) null, randomBoolean());
-        return new Option(text, highlighted, score, collateMatch);
+        return new PhraseSuggestion.Entry.Option(text, highlighted, score, collateMatch);
     }
 
     public void testFromXContent() throws IOException {
@@ -66,7 +67,7 @@ public class SuggestionOptionTests extends ESTestCase {
         Option parsed;
         try (XContentParser parser = createParser(xContentType.xContent(), mutated)) {
             ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.nextToken(), parser::getTokenLocation);
-            parsed = Option.fromXContent(parser);
+            parsed = PhraseSuggestion.Entry.Option.fromXContent(parser);
             assertEquals(XContentParser.Token.END_OBJECT, parser.currentToken());
             assertNull(parser.nextToken());
         }
@@ -78,7 +79,7 @@ public class SuggestionOptionTests extends ESTestCase {
     }
 
     public void testToXContent() throws IOException {
-        Option option = new Option(new Text("someText"), new Text("somethingHighlighted"), 1.3f, true);
+        Option option = new PhraseSuggestion.Entry.Option(new Text("someText"), new Text("somethingHighlighted"), 1.3f, true);
         BytesReference xContent = toXContent(option, XContentType.JSON, randomBoolean());
         assertEquals("{\"text\":\"someText\","
                       + "\"highlighted\":\"somethingHighlighted\","

server/src/test/java/org/elasticsearch/search/suggest/SuggestionTests.java

@@ -188,14 +188,15 @@ public class SuggestionTests extends ESTestCase {
     public void testToXContent() throws IOException {
         ToXContent.Params params = new ToXContent.MapParams(Collections.singletonMap(RestSearchAction.TYPED_KEYS_PARAM, "true"));
         {
-            Option option = new Option(new Text("someText"), new Text("somethingHighlighted"), 1.3f, true);
-            Entry<Option> entry = new Entry<>(new Text("entryText"), 42, 313);
+            PhraseSuggestion.Entry.Option option = new PhraseSuggestion.Entry.Option(new Text("someText"), new Text("somethingHighlighted"),
+                1.3f, true);
+            PhraseSuggestion.Entry entry = new PhraseSuggestion.Entry(new Text("entryText"), 42, 313);
             entry.addOption(option);
-            Suggestion<Entry<Option>> suggestion = new Suggestion<>("suggestionName", 5);
+            PhraseSuggestion suggestion = new PhraseSuggestion("suggestionName", 5);
             suggestion.addTerm(entry);
             BytesReference xContent = toXContent(suggestion, XContentType.JSON, params, randomBoolean());
             assertEquals(
-                    "{\"suggestion#suggestionName\":[{"
+                    "{\"phrase#suggestionName\":[{"
                             + "\"text\":\"entryText\","
                             + "\"offset\":42,"
                             + "\"length\":313,"
@@ -208,7 +209,8 @@ public class SuggestionTests extends ESTestCase {
                     + "}", xContent.utf8ToString());
         }
         {
-            Option option = new Option(new Text("someText"), new Text("somethingHighlighted"), 1.3f, true);
+            PhraseSuggestion.Entry.Option option = new PhraseSuggestion.Entry.Option(new Text("someText"), new Text("somethingHighlighted"),
+                    1.3f, true);
             PhraseSuggestion.Entry entry = new PhraseSuggestion.Entry(new Text("entryText"), 42, 313, 1.0);
             entry.addOption(option);
             PhraseSuggestion suggestion = new PhraseSuggestion("suggestionName", 5);

test/framework/src/main/java/org/elasticsearch/index/engine/EngineTestCase.java

@@ -460,7 +460,7 @@ public abstract class EngineTestCase extends ESTestCase {
                 TimeValue.timeValueMinutes(5), refreshListenerList, Collections.emptyList(), indexSort, handler,
                 new NoneCircuitBreakerService(),
                 globalCheckpointSupplier == null ?
-                    new ReplicationTracker(shardId, allocationId.getId(), indexSettings, SequenceNumbers.NO_OPS_PERFORMED) :
+                    new ReplicationTracker(shardId, allocationId.getId(), indexSettings, SequenceNumbers.NO_OPS_PERFORMED, update -> {}) :
                     globalCheckpointSupplier, primaryTerm::get);
         return config;
     }

test/framework/src/main/java/org/elasticsearch/test/InternalTestCluster.java

@@ -2008,8 +2008,10 @@ public final class InternalTestCluster extends TestCluster {
                 final CircuitBreakerService breakerService = getInstanceFromNode(CircuitBreakerService.class, nodeAndClient.node);
                 CircuitBreaker fdBreaker = breakerService.getBreaker(CircuitBreaker.FIELDDATA);
                 assertThat("Fielddata breaker not reset to 0 on node: " + name, fdBreaker.getUsed(), equalTo(0L));
-                CircuitBreaker acctBreaker = breakerService.getBreaker(CircuitBreaker.ACCOUNTING);
-                assertThat("Accounting breaker not reset to 0 on node: " + name, acctBreaker.getUsed(), equalTo(0L));
+                // TODO: This is commented out while Lee looks into the failures
+                // See: https://github.com/elastic/elasticsearch/issues/30290
+                // CircuitBreaker acctBreaker = breakerService.getBreaker(CircuitBreaker.ACCOUNTING);
+                // assertThat("Accounting breaker not reset to 0 on node: " + name, acctBreaker.getUsed(), equalTo(0L));
                 // Anything that uses transport or HTTP can increase the
                 // request breaker (because they use bigarrays), because of
                 // that the breaker can sometimes be incremented from ping

test/framework/src/main/java/org/elasticsearch/transport/nio/MockNioTransport.java

@@ -40,9 +40,11 @@ import org.elasticsearch.nio.NioServerSocketChannel;
 import org.elasticsearch.nio.NioSocketChannel;
 import org.elasticsearch.nio.ServerChannelContext;
 import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.transport.ConnectionProfile;
 import org.elasticsearch.transport.TcpChannel;
 import org.elasticsearch.transport.TcpServerChannel;
 import org.elasticsearch.transport.TcpTransport;
+import org.elasticsearch.transport.TransportRequestOptions;
 import org.elasticsearch.transport.Transports;
 
 import java.io.IOException;
@@ -51,6 +53,8 @@ import java.net.StandardSocketOptions;
 import java.nio.ByteBuffer;
 import java.nio.channels.ServerSocketChannel;
 import java.nio.channels.SocketChannel;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.concurrent.ConcurrentMap;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
@@ -128,6 +132,34 @@ public class MockNioTransport extends TcpTransport {
         profileToChannelFactory.clear();
     }
 
+    @Override
+    protected ConnectionProfile resolveConnectionProfile(ConnectionProfile connectionProfile) {
+        ConnectionProfile resolvedProfile = resolveConnectionProfile(connectionProfile, defaultConnectionProfile);
+        if (resolvedProfile.getNumConnections() <= 3) {
+            return resolvedProfile;
+        }
+        ConnectionProfile.Builder builder = new ConnectionProfile.Builder();
+        Set<TransportRequestOptions.Type> allTypesWithConnection = new HashSet<>();
+        Set<TransportRequestOptions.Type> allTypesWithoutConnection = new HashSet<>();
+        for (TransportRequestOptions.Type type : TransportRequestOptions.Type.values()) {
+            int numConnections = resolvedProfile.getNumConnectionsPerType(type);
+            if (numConnections > 0) {
+                allTypesWithConnection.add(type);
+            } else {
+                allTypesWithoutConnection.add(type);
+            }
+        }
+
+        // make sure we maintain at least the types that are supported by this profile even if we only use a single channel for them.
+        builder.addConnections(3, allTypesWithConnection.toArray(new TransportRequestOptions.Type[0]));
+        if (allTypesWithoutConnection.isEmpty() == false) {
+            builder.addConnections(0, allTypesWithoutConnection.toArray(new TransportRequestOptions.Type[0]));
+        }
+        builder.setHandshakeTimeout(resolvedProfile.getHandshakeTimeout());
+        builder.setConnectTimeout(resolvedProfile.getConnectTimeout());
+        return builder.build();
+    }
+
     private void exceptionCaught(NioSocketChannel channel, Exception exception) {
         onException((TcpChannel) channel, exception);
     }

test/framework/src/test/java/org/elasticsearch/transport/nio/SimpleMockNioTransportTests.java

@@ -94,6 +94,11 @@ public class SimpleMockNioTransportTests extends AbstractSimpleTransportTestCase
         return transportService;
     }
 
+    @Override
+    protected int channelsPerNodeConnection() {
+        return 3;
+    }
+
     @Override
     protected void closeConnectionChannel(Transport transport, Transport.Connection connection) throws IOException {
         TcpTransport.NodeChannels channels = (TcpTransport.NodeChannels) connection;